Answer:
j=13, g=20.8, h=24
Step-by-step explanation:
The overall shape given and the shape within, are both right triangles. With right triangles, you are allowed to use the pythagorean theorem formula ([tex]a^{2} + b^{2} = c^{2}[/tex]) in order to solve for some sides. In this case, that would be j and h. The five in the smaller triangle is represented by b and the 12 is the hypotenuse so it is represented by c. When you plug in those numbers in the pythagorean theorem formula, you will find the value of j to be 13. When looking at this, we see that 12 is the second greatest value in the right triangle values that we just found, so we know the the opposing angle for that one will be 60 degrees. The 5's opposing side is therefore 30 degrees. When subtracting 90 and 30, we get 60, so therefore you can use the 30 60 90 formula to find the sides of the bigger triangle. The 60 degrees represents g. This formula will be [tex]a\sqrt{3}[/tex]. The a is 12 since it is the smallest value. So therefore, g is [tex]12\sqrt{3}[/tex], which is 20.8. Now that we have this side, we can just use the pythagorean theorem formula to find the remaining side. Therefore, h is going to be 24
Can someone help me with this?
x^2-4x+4
I understand -2 x 2=-4, but I’m not seeing how to add the factors to get +4, because -2+2=0. I’ve got the first half of the solution, but not the second.
Answer:
(x-2)(x-2)
Step-by-step explanation:
You should be trying to find two numbers that add to make the coefficient of x (in this case, -4), and two numbers that multiply to make the constant term (in this case, +4). The two numbers that work for both of those criteria are -2 and -2.
-2 x -2 = +4 (satisfies the constant term)
-2 + -2 = -4 (satisfies the coefficient of x)
someone pls help me ! i rlly need help
Answer:
Option D is the correct answer.
Step-by-step explanation:
Coefficients od dividend = (4, - 17, - 15)
Dividend [tex]=4x^2 - 17x - 15[/tex]
Divisor x = 5 =>x-5= 0
Coefficients of Quotient = (4, 3)
Quotient [tex]=4x + 3[/tex]
Remainder = 0
Since,
[tex] Dividend = Divisor \times quotient + Remainder\\
\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) +0 \\
\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) \\
\therefore( 4x^2 - 17x - 15) \div (x - 5) = (4x + 3)
[/tex]
Determine whether the description corresponds to an observational study or an experiment.
Research is conducted to determine if there is a relation between hearing loss and exposure to mumps. exposure to mumps.
Does the description correspond to an observational study or an experiment?
A. Observational study
B. Experiment
Answer:
A. Observational study
Step-by-step explanation:
In research, an observational study is a type of study in which the researcher observes a phenomenon and tries to establish some relationship between the different variables he/she is observing. In other words, the researcher only observes and doesn't give a treatment.
On the other hand, when we have a experiment, we usually have 2 different groups (one that will receive a treatment and one who won't) and the researcher compares the differences between these two groups because of the treatment. In other words, the researcher does something other than just observing.
In this example, the research is going to determine if there is a relation between hearing loss and exposure to mumps. In this example the researcher is only going to observe how people who have been exposed to mumps are regarding hearing loss (we can say this since it will be unethical for example for the researcher to create an experiment in which he/she exposes a group to mumps). Therefore, he is going to observe how the past exposure to mumps could be related with the hearing loss.
Thus, this is an observational study.
Triangle QRS is dilated according to the rule DO,2 (x,y). On a coordinate plane, (0, 0) is the center of dilation. Triangle Q R S has points (negative 3, 3), (2, 4), and (negative 1, 1). What is true about the image ΔQ'R'S'? Select three options. Which statements are true? DO,2 (x,y) = (2x, 2y) Side Q'S' lies on a line with a slope of -1. QR is longer than Q'R'. The vertices of the image are closer to the origin than those of the pre-image. The distance from Q' to the origin is twice the distance from Q to the origin.
Answer:
Options A, B and E are correct
Step-by-step explanation:
From the information given above, we would draw a dilation that produces an image that is the same shape as the original image, but has a different size.
The scale factor is 2
QRS → Q'R'S' = (x,y) → 2(x,y)
The coordinates of ∆QRS
Q (-3, 3)
R (2, 4)
S (-1, 1)
To get the coordinates of Q'R'S', we would multiply each coordinate of the original triangle by the scale factor of 2 since the dilation is from the origin. In order words, each vertex of QRS is multiplied by 2 to get each of the vertex of Q'R'S'.
2 (x,y) = (2x, 2y)
The coordinates of ∆Q'R'S' becomes:
Q' (-6, 6)
R' (4, 8)
S' (-2, 2)
To determine the statements that are true about the image ΔQ'R'S,
we would graph the coordinates of the two triangles.
Starting with ΔABC, we would draw the dilation image of the triangle with a center at the origin and a scale factor of 2.
See attached the diagram for better explanation.
Let's check out each options and compare it with diagram we obtained:
a) DO, 2 (x,y) = (2x, 2y)
A dilation about the origin with a scale factor 2 is described using the above notation.
Q' = 2(-3,3) = [2(-3), 2(3)] = (-6, 6)
R' (4, 8) = 2(2,4) = [2(2), 2(4)] = (4, 8)
S' (-2, 2) = 2(-1,1) = [2(-1), 2(1)] = (-2, 2)
This option is correct
b) Side Q'S' lies on a line with a slope of -1
Q' (-6, 6)
S' (-2, 2)
coordinate (x, y)
Slope = m = (change in y)/(change in x)
m = (6-2)/[-6-(-2)]
= 4/(-6+2) = 4/-4
m = -1
This option is correct
c) QR is longer than Q'R'
Length of QR (-3 to 2) = 5
Length of Q'R' (-6 to 4) = 10
QR is not longer than Q'R'
This option is false
d) The vertices of the image are closer to the origin than those of the pre-image
The scale factor determines how much bigger or smaller the dilation image will be compared to the preimage. In a transformation, the final figure is referred to as the image. The original figure is referred to as the preimage.
From the diagram, the vertices of the preimage (original image) are closer to the origin than those of the dilation image.
This option is false
e) The distance from Q' to the origin is twice the distance from Q to the origin.
The distance from Q' to the origin (6 to 0) = 6
The distance from Q to the origin (3 to 0) = 3
The distance from Q' to the origin = 2(the distance from Q to the origin)
This option is correct
Answer:
A,B and E is correct
Step-by-step explanation:
Deepak is a landscaper who charges $30 for each job he does plus an additional $15 for each hour he works. He only accepts jobs if he will earn at least $90 the job. He writes this inequality to determine x, the number of hours he must work during each job in order to accomplish this.
30 + 15 x greater-than-or-equal-to 90
Which best describes the restrictions on the jobs Deepak will accept?
He only accepts jobs that last 4 or more hours.
He only accepts jobs that last 5 or more hours.
He only accepts jobs that last 8 or more hours.
He only accepts jobs that last 9 or more hours.
Hey there! I'm happy to help!
The only thing we have to do is solve our inequality to find the answer!
30+15x ≥ 90
We subtract 30 from both sides.
15x ≥ 60
Finally, we divide both sides by four.
x ≥ 4
Therefore, Deepak can only accept jobs that last 4 or more hours.
I hope that this helps! Have a wonderful day!
The solution for the inequality is x≥4. Therefore, option A is the correct answer.
Given that, Deepak is a landscaper who charges $30 for each job he does plus an additional $15 for each hour he works.
What are inequalities?Inequalities are the mathematical expressions in which both sides are not equal. In inequality, unlike in equations, we compare two values. The equal sign in between is replaced by less than (or less than or equal to), greater than (or greater than or equal to), or not equal to sign.
The inequality for the given situation is 30+15x≥90
Subtract 30 on the both the sides of an inequality, which is
30+15x-30≥90-30
⇒ 15x≥60
Divide 15 on the both the sides of an inequality, that is
15x/15≥60/15
⇒ x≥4
The solution for the inequality is x≥4. Therefore, option A is the correct answer.
To learn more about the inequalities visit:
https://brainly.com/question/20383699.
#SPJ5
Life tests performed on a sample of 13 batteries of a new model indicated: (1) an average life of 75 months, and (2) a standard deviation of 5 months. Other battery models, produced by similar processes, have normally distributed life spans. The 98% confidence interval for the population mean life of the new model is _________. Group of answer choices
Answer:
(71.28, 78.72)
Step-by-step explanation:
We have the following information from the statement:
mean (m) = 75
sample standard deviation (sd) = 5
Sample size (n) = 13
Significance level (alpha) = 1 - 0.98 = 0.02
Degrees of freedom for t-d (df) = n - 1 = 13 - 1 = 12
The critical value would be:
t (alpha / 2) / df = T (0.01) / 12 = 2,681 (this for the table)
Margin of error equals:
E = t (alpha / 2) / df * sd / n ^ (1/2), replacing:
E = 2,681 * 5/13 ^ (1/2)
E = 3.72
Therefore, the interval of 98% confidence interval would be:
75 + 3.72 = 78.72
75 - 3.72 = 71.28
(71.28, 78.72)
Can You please help me cause I'm gangsta Simplify (5^-2)^4
Answer:
( 5 ^ -2)^4
= 5 ^ -8
= 1 /5^8
= 1 / 390,625
Florian ran 1.2 miles and walked 4.8 laps around the path at the park for a total distance of 3.6 miles. Which shows the correct equation and value of x, the distance of 1 lap around the path at the park? 3.6 x + 1.2 = 4.8; x = 1 mile 4.8 x + 1.2 = 3.6; x = 1 mile 3.6 x + 1.2 = 4.8; x = 0.5 mile 4.8 x + 1.2 = 3.6; x = 0.5 mile
Answer:
The correct answer would be D) 4.8x + 1.2 = 3.6; x = 0.5 mile
Step-by-step explanation:
This is because laps would be the dependent variable, so we know the number of them (4.8) would be multiplied by the variable (x). We also know that 1.2 is the constant. Now we can solve to make sure this is the right equation.
4.8x + 1.2 = 3.6
4.8x = 2.4
x = 0.5
Answer:
D) 4.8x + 1.2 = 3.6; x = 0.5 miles
Write an equation in slope-intercept form for the line that passes through (0,1) and (1,3)
Answer:
y= 2x+1
Step-by-step explanation:
Points:
(0,1) and (1,3)Form of the line:
y=mx+b, m- the slope, b- y-interceptFinding the slope:
m= (y2-y1)/(x2-x1)m=(3-1)/(1-0)= 2/1= 2Line is now:
y= 2x+bUsing one of the given points to find out the value of b:
1=2*0+bb=1So the equation for the line is:
y= 2x+1Which value of y makes the equation y/9=12 true
Answer:
108
Step-by-step explanation:
9 times 12 is 108
Maya is going to rent a truck for one day. There are two companies she can choose from, and they have the following prices. Company A has no initial fee but charges 80 cents for every mile driven. Company B charges an initial fee of $65 and an additional cents for every mile driven. For what mileages will Company A charge more than Company B? Use m for the number of miles driven, and solve your inequality for m .
Answer:
m > 82.28
Step-by-step explanation:
Price to Pay (P)
distance (m)
Company A
Pa = 0.80m
Company B
Pb = 65 + 0.01m
Company A charge more than B is written like this
0.8m > 65 + 0.01m
then we can solve this inequality
(0.8 - 0.01)m > 65
0.79m > 65
m > 65/0.79
m > 82.28 miles
so if Maya will go more than 82.28 miles, I suggest Company B is cheaper
I will mark brainly-ist to who ever helps me
Find the value of the logarithm.
log 110
Round your answer to the nearest thousandth.
Answer:
4.700
Step-by-step explanation:
Find the number in the thousandth place 0 and look one place to the right for the rounding digit 4. Round up if this number is greater than or equal to 5 and round down if it is less than 5.
brainliesssss plssssssssssssss
Im stuck who can help me
Answer:
Option D
Step-by-step explanation:
This question is based on the " Partition Postulate. " You might be familiar with it, it states that a whole is composed of several parts. In this case you could say that this " whole " is ∠ ABC, and the " parts " are ∠1 and ∠2. By this Theorem you could also state the following;
[tex]m< ABC = m< 1 + m< 2,\\\\Substitute,\\110 = 4x + ( 5x + 10 ),\\110 = 4x + 5x + 10,\\4x + 5x + 10 = 110 - Option D\\\\Solution - Option D[/tex]
Hope that helps!
which answer shows 9 x 10 ^ -5 written in standard form ?
A -0.000009
B -0.00009
C 0.0009
D 0.00009
Answer:
D 0.00009
Step-by-step explanation:
9 × 10^-5 = 9 × 1/10^5 = 9 × 1/100,000
= 9 × 0.00001
= 0.00009
_____
Comment on place value
The exponent of 10 associated with the place value in a decimal number increases from 0 to the left of the decimal point, and decreases from -1 to the right of the decimal point:
100. = 10²
10. = 10¹
1. = 10⁰
0.1 = 10⁻¹
0.01 = 10⁻²
0.001 = 10⁻³
0.0001 = 10⁻⁴
0.00001 = 10⁻⁵
This simple realization can help you immensely with scientific notation.
1/4x - 2/5 =39 someone please answer this question thx
Answer:
157.6
Step-by-step explanation:
Use PEMDAS! In this rule, it is stated that we should always add/subtract before multiplying/dividing. Also, whatever you do on one side of an equation, you do to another. Therefore, in order to get rid of the -2/5, add 2/5 so we can get rid of it. We also (according to the rule), have to add it to the other side in order to balance out. So add the 2/5 to 39. Then the other side is now 39.4. Now we have to get x by itself. Divide both sides by 1/4 (or multiply by 4 on both sides) in order to get x=157.6
The price of a ring was increased by 9% to £1800. What was the price before the increase? Give your answer to the nearest penny.
Answer:
1651
Step-by-step explanation:
let s say that the price before the increase is x
to apply an increase of 9% it does x + x*0.09 = x*(1+0.09)=x*1.09
and we know that this value is 1800
so
x*1.09=1800
<=>
x = 1800/1.09=1651.376147
to the nearest penny it gives 1651
Answer:
Hello!
Answer: 1651
I hope that was correct. Please let me know, thank you!
Step-by-step explanation:
which is a correct first step in solving the inequality-4(2x-1)>5-3x
Step-by-step explanation:
-8x + 4 > 5 - 3x
-8x + 3x > 5 - 4
-5x > 1
x > 1 / - 5
3. Match each staternent with an expression that could be used to find the price
p+ 0.3p
0.7p
e. 85% more than the original time
f 15% less time than the original
g. 85% time decrease
h, 15% time increase
17p
p-07p
I
4. Ronnie increased the amount of money in his piggy bank by 25%. Which expres
find the amount of money in his bank? Let "m" represent the original
Answer:
3a) 30% more than original price
b) 70% of the original price
c) 17times the original price
d) 70% less than original price
e) t + 0.85t
f) t - 0.15t
g) t - 0.85t
h) t + 0.15t
4. The expression that can be used to find the amount of money in his bank = m + 0.25m
Question:
3. Match each statement with an expression that could be used to find the price.
'The expressions for a to d were not stated in the question'.
a) p+ 0.3p
b) 0.7p
c) 17p
d) p-07p
'From e to h, we were not told what to determine'.
Write the expression in terms of time
e. 85% more than the original time
f. 15% less time than the original
g. 85% time decrease
h. 15% time increase
4. Ronnie increased the amount of money in his piggy bank by 25%. Which expression can be used to find the amount of money in his bank? Let "m" represent the original.
Step-by-step explanation:
let original price = p
a) p+ 0.3p = p + 30% of p
30% more than original price
b) 0.7p = 70% of p
= 70% of the original price
c) 17p = 17 × p
= 17times of the original price
d) p-0.7p = p - 70% of p
= 70% less than original price
Let original time = t
e) 85% more than the original time = t + 85%of t
= t + 0.85t
f) 15% less time than the original time = t - 15% of t
= t - 0.15t
g) 85% time decrease = t - 85% of t
= t - 0.85t
h) 15% time increase = t + 15% of t
= t + 0.15t
4. Since "m" represent the original amount in Hus piggy bank
An increase of 25% = original amount + 25% of original amount
= m + 25% of m
'Of' means multiplication
= m + 0.25 ×m
= m + 0.25m
= 1.25m
The expression that can be used to find the amount of money in his bank = m + 0.25m
What is the final step in solving the inequality –2(5 – 4x) < 6x – 4?
Answer:
–2(5 – 4x) < 6x – 4
<=>
-10 + 8x < 6x - 4
<=>
2x < 6
<=>
x < 3
Hope this helps!
:)
Answer:
Step 1: –10 + 8x < 6x – 4
Step 2: –10 < –2x – 4
Step 3: –6 < –2x
Step 4: ________
What is the final step in solving the inequality –2(5 – 4x) < 6x – 4?
A. x < –3
B. x > –3
C. x < 3
D. x > 3
Step-by-step explanation:
The correct answer here is C. x < 3
Find the slope of the line: 3x-2y=6
Answer:
slope = 3/2
Step-by-step explanation:
3x-2y=6
Get this equation in the form y = mx+b where m is the slope and b is the y intercept
Subtract 3x from each side
3x-3x-2y=-3x+6
-2y = -3x+6
Divide each side by -2
-2y/-2 = -3x/-2 +6/-2
y = 3/2x -3
The slope is 3/2 and the y intercept is -3
Answer:
3/2
Step-by-step explanation:
I got this answer by putting it in the form y=mx+b
Step 1: Subtract 3x from each side
-2y = -3x+6
Step 2: Divide each side by -2
y = 3/2x -3
The slope is 3/2 and the y intercept is -3 because m is the slope and b is the y-intercept.
A bag contains 4 green, 5 red, and 6 purple balls. The probability that all of them are red is?
Answer:
The percentage would be 20% (5x20=100)
Step-by-step explanation:
f(x)=x^2-2x+3; f(x)=-2x+28
Answer:
(-5, 38) and
(5,18)
Step-by-step explanation:
[tex]x^2-2x+3=-2x+28\\<=> x^2-2x+3+2x=28\\<=> x^2 = 28-3=25\\<=> x^2-25=0\\<=> x^2-5^2 =0\\<=> (x-5)(x+5)=0\\<=> x = 5 \ or \ x=-5[/tex]
so the solutions are
(-5, 38) and
(5,18)
3. In 28 days, a person saved $42. What was this person's
average daily savings?
Answer:
The average would be 42 / 28 = $1.50 / day.
Answer:
$1.50 per day
Step-by-step explanation:
Take the dollar amount and divide by the number of days
42 dollars / 28 days
1.50 dollars per day
$1.50 per day
The function f determines the volume of the box (in cubic inches) given a cutout length (in inches). Use function notation to represent the volume of the box (in cubic inches) when the cutout length is 0.2 inches. Use function notation to represent the volume of the box (in cubic inches) when the cutout length is 1.3 inches. Use function notation to represent how much the volume of the box (in cubic inches) changes by if the cutout length increases from 0.2 inches to 1.3 inches. Use function notation to represent how much the volume of the box (in cubic inches) changes by if the cutout length increases from 5.5 inches to 5.6 inches.
Complete Question
A box is formed by cutting squares from the four corners of a sheet of paper and folding up the sides. However, the size of the paper is unknown!
Answer:
(a)[tex]f(0.2)=0.2(l-0.4)(w-0.4)[/tex]
(b)[tex]f(1.3)=1.3(l-2.6)(w-2.6)[/tex]
(c)f(1.3)-f(0.2)
(d) f(5.6)-f(5.5)
Step-by-step explanation:
Let the Length of the paper =l (in inches)
Let the Width of the paper =w (in inches)
Let the length of the cutout square = x (in inches)
Base Length of the Box = l-2xBase Width of the box =w-2xHeight of the box =xVolume of the box: [tex]f(x)=x(l-2x)(w-2x)[/tex]
(a)When the cutout length is 0.2 inches.
x=0.2
Volume of the box (in cubic inches) ,
[tex]f(0.2)=0.2(l-0.4)(w-0.4)[/tex]
(b)When the cutout length is 01.3 inches.
x=1.3
Volume of the box (in cubic inches) ,
[tex]f(1.3)=1.3(l-2.6)(w-2.6)[/tex]
(c)If the cutout length increases from 0.2 inches to 1.3 inches.
Change In volume (in cubic inches):
[tex]f(1.3)-f(0.2)\\=1.3(l-2.6)(w-2.6)-0.2(l-0.4)(w-0.4)[/tex]
(d)If the cutout length increases from 5.5 inches to 5.6 inches.
Change In volume (in cubic inches):
[tex]f(5.6)-f(5.5)\\=5.6(l-11.2)(w-11.2)-5.5(l-11)(w-11)[/tex]
URGENT!! EASY IM DUMB MY LAST QUESTION WILL FOREVER BE GRATEFUL PLS HELP WILL GIVE BRANLIEST!! AT LEAST TAKE A LOOK!!!! PLS I AM BEGGING!!!
18. Using the diagram below as reference, write a paragraph proof to prove that the symmetric property of congruence exists for any two angles. (IMAGE BELOW)
Given: ∠A is congruent to ∠B
Prove: ∠B is congruent to ∠A
Plan: Show that ∠A and ∠B have the same measure, thus ∠B and ∠A have the same measure under symmetry for equality. Conclude with ∠B being congruent to ∠A.
Answer:
Below.
Step-by-step explanation:
18. Since A is congruent to B, you can conclude that B is congruent to A by the Reflexive Property of Congruence.
A standard 52-card deck has four 13-card suits: diamonds, hearts, clubs, and spades. The diamonds and hearts are red, and the clubs and spades are black. Each 13-card suit contains cards numbered from 2 to 10, a jack, a queen, a king, and an ace. An experiment consists of drawing 1 card from the standard deck. Find the probability of drawing a black jack of diamonds.
Answer:
0
Step-by-step explanation:
In a suit of 52 cards
The Red Cards are: diamonds and heartsThe Black cards are: clubs and spadesThe experiment consists of drawing 1 card from the standard deck.
Since diamonds are red, there is no black jack of diamonds.
Therefore:
P(drawing a black jack of diamonds)
[tex]=\dfrac{0}{52}\\\\ =0[/tex]
Answers:
In photo below
Explanation:
I got it correct in my test :)
is the square root of 5/8 rational or irrational
Answer:
the answer is square root 5 over 2 square root 2
Step-by-step explanation:
During the calendar year of 1971 a total of 171 deaths were caused by influenza in a city of 450,000 persons. The temporal distribution of these deaths was as follows: First Quarter, 54; Second Quarter, 43; Third Quarter, 35; and Fourth Quarter, 39. Calculate the annual and quarterly mortality rates per 100,000 population.
Answer and Step-by-step explanation:
The computation of annual and quarterly mortality rates per 100,000 population is shown below:-
Quarterly mortality rates are
[tex]= \frac{Deaths}{Population\ in\ the\ city}\times Population[/tex]
For the first quarter
[tex]= \frac{54}{450,000}\times 100,000[/tex]
= 12 death per 100,000 population
For the second quarter
[tex]= \frac{43}{450,000}\times 100,000[/tex]
= 9.5 death per 100,000 population
For the third quarter
[tex]= \frac{35}{450,000}\times 100,000[/tex]
= 7.7 death per 100,000 population
For the fourth quarter
[tex]= \frac{39}{450,000}\times 100,000[/tex]
= 8.6 death per 100,000 population
Now the annual mortality is
[tex]= \frac{Deaths}{Population\ in\ the\ city}\times Population[/tex]
[tex]= \frac{171}{450,000}\times 100,000[/tex]
= 38 death per 100,000 population
In determining automobile-mileage ratings, it was found that the mpg (X) for a certain model is normally distributed, with a mean of 33 mpg and a standard deviation of 1.7 mpg. Find the following:__________.
a. P(X<30)
b. P(28
c. P(X>35)
d. P(X>31)
e. the mileage rating that the upper 5% of cars achieve.
Answer:
a) P(X < 30) = 0.0392.
b) P(28 < X < 32) = 0.2760
c) P(X > 35) = 0.1190
d) P(X > 31) = 0.8810
e) At least 35.7965 mpg
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 33, \sigma = 1.7[/tex]
a. P(X<30)
This is the pvalue of Z when X = 30. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{30 - 33}{1.7}[/tex]
[tex]Z = -1.76[/tex]
[tex]Z = -1.76[/tex] has a pvalue of 0.0392.
Then
P(X < 30) = 0.0392.
b) P(28 < X < 32)
This is the pvalue of Z when X = 32 subtracted by the pvalue of Z when X = 28. So
X = 32
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{32 - 33}{1.7}[/tex]
[tex]Z = -0.59[/tex]
[tex]Z = -0.59[/tex] has a pvalue of 0.2776.
X = 28
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{28 - 33}{1.7}[/tex]
[tex]Z = -2.94[/tex]
[tex]Z = -2.94[/tex] has a pvalue of 0.0016.
0.2776 - 0.0016 = 0.2760.
So
P(28 < X < 32) = 0.2760
c) P(X>35)
This is 1 subtracted by the pvalue of Z when X = 35. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{35 - 33}{1.7}[/tex]
[tex]Z = 1.18[/tex]
[tex]Z = 1.18[/tex] has a pvalue of 0.8810.
1 - 0.8810 = 0.1190
So
P(X > 35) = 0.1190
d. P(X>31)
This is 1 subtracted by the pvalue of Z when X = 31. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{31 - 33}{1.7}[/tex]
[tex]Z = -1.18[/tex]
[tex]Z = -1.18[/tex] has a pvalue of 0.1190.
1 - 0.1190 = 0.8810
So
P(X > 31) = 0.8810
e. the mileage rating that the upper 5% of cars achieve.
At least the 95th percentile.
The 95th percentile is X when Z has a pvalue of 0.95. So it is X when Z = 1.645. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.645 = \frac{X - 33}{1.7}[/tex]
[tex]X - 33 = 1.645*1.7[/tex]
[tex]X = 35.7965[/tex]
At least 35.7965 mpg
The upper 5% of cars have a mileage rating of 35.805 mpg
What is z score?Z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by:
z = (raw score - mean) / standard deviation
Given; mean of 33 mpg and a standard deviation of 1.7
a) For < 30:
z = (30 - 33)/1.7 = -1.76
P(x < 30) = P(z < -1.76) = 1 - 0.8413 = 0.0392
b) For < 28:
z = (28 - 33)/1.7 = -2.94
P(x < 28) = P(z < -2.94) = 0.0016
c) For > 35:
z = (35 - 33)/1.7 = 1.18
P(x > 35) = P(z > 1.18) = 1 - P(z < 1.18) = 1 - 0.8810 = 0.119
d) For > 31:
z = (31 - 33)/1.7 = -1.18
P(x > 31) = P(z > -1.18) = 1 - P(z < -1.18) = 0.8810
e) The upper 5% of cars achieve have a z score of 1.65, hence:
1.65 = (x - 33)/1.7
x = 35.805 mpg
The upper 5% of cars have a mileage rating of 35.805 mpg
Find out more on z score at: https://brainly.com/question/25638875
The lifespan (in days) of the common housefly is best modeled using a normal curve having mean 22 days and standard deviation 5. Suppose a sample of 25 common houseflies are selected at random. Would it be unusual for this sample mean to be less than 19 days?
Answer:
Yes, it would be unusual.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
If [tex]Z \leq -2[/tex] or [tex]Z \geq 2[/tex], the outcome X is considered unusual.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question, we have that:
[tex]\mu = 22, \sigma = 5, n = 25, s = \frac{5}{\sqrt{25}} = 1[/tex]
Would it be unusual for this sample mean to be less than 19 days?
We have to find Z when X = 19. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{19 - 22}{1}[/tex]
[tex]Z = -3[/tex]
[tex]Z = -3 \leq -2[/tex], so yes, the sample mean being less than 19 days would be considered an unusual outcome.