Answer:
x = 6; y = -6
Step-by-step explanation:
-4x - 2y = -12
4x + 8y = -24
Add the two equations, so x is eliminated:
6y = -36
6y/6 = -36/6
y = -6
Plug in y, to solve for x
-4x - 2y = -12
-4x - 2(-6) = -12
-4x +12 = -12
-4x = -12 -12
-4x = -24
-4x/-4 = -24/-4
x = 6
Answer from Gauthmath
Adam sleeps for nine hours each night, five nights a week, and 11 hours for two nights a week.
Which is closest to the percentage of the whole week that Adam spends sleeping?
A) 25%
B) 30%
C) 33%
D) 40%
E) 50%
Answer:
E
Step-by-step explanation:
The percentage of the whole week that Adam spends in sleeping is 33%.
What is percentage?
A percentage is a portion of a whole expressed as a number between 0 and 100 rather than as a fraction.
How to find percentage of a number?A percentage is a number or ratio that can be expressed as a fraction of 100. If we have to calculate percent of a number, divide the number by the whole and multiply by 100.
According to the give question.
Adams sleeps for nine hours each night, five nights a week.
⇒ Number of hours he sleep for five nights = 5 × 9 = 45 hours
Also, 11 hours for two nights a week.
So, the total number of hours Adam sleeps in a week = 45 + 11 = 56 hours
And, total number of hours in a week = 24 × 7 = 168
Therefore,
The percentage of the whole week that Adam spends in sleeping
= (total number of hours Adam sleep in a week/Total numbers of hour in a week) × 100
[tex]=\frac{56}{168}[/tex] × 100
= 33.33%
= 33%
Hence, the percentage of the whole week that Adam spends in sleeping is 33%.
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Full-time Ph.D. students receive an average of $12,837 per year. If the average salaries are normally distributed with a standard deviation of $1500, find these probabilities. a. The student makes more than $15,000. b. The student makes between $13,000 and $14,000.
Answer:
a) 0.0749 = 7.49% probability that the student makes more than $15,000.
b) 0.227 = 22.7% probability that the student makes between $13,000 and $14,000.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Full-time Ph.D. students receive an average of $12,837 per year.
This means that [tex]\mu = 12837[/tex]
Standard deviation of $1500
This means that [tex]\sigma = 1500[/tex]
a. The student makes more than $15,000.
This is 1 subtracted by the p-value of Z when X = 15000.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{15000 - 12837}{1500}[/tex]
[tex]Z = 1.44[/tex]
[tex]Z = 1.44[/tex] has a p-value of 0.9251.
1 - 0.9251 = 0.0749
0.0749 = 7.49% probability that the student makes more than $15,000.
b. The student makes between $13,000 and $14,000.
This is the p-value of Z when X = 14000 subtracted by the p-value of Z when X = 13000.
X = 14000
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{14000 - 12837}{1500}[/tex]
[tex]Z = 0.775[/tex]
[tex]Z = 0.775[/tex] has a p-value of 0.7708.
X = 13000
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{13000 - 12837}{1500}[/tex]
[tex]Z = 0.11[/tex]
[tex]Z = 0.11[/tex] has a p-value of 0.5438.
0.7708 - 0.5438 = 0.227
0.227 = 22.7% probability that the student makes between $13,000 and $14,000.
7.49% of the student makes more than $15,000, while 23.85% of the student makes between $13,000 and $14,000
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 that:
Mean = $12837, standard deviation = $1500
a) For >15000:
z = (15000 - 12837)/1500 = 1.44
P(z > 1.44) = 1 - P(z < 1.44) = 1 - 0.9251 = 0.0749
b) For >13000:
z = (13000 - 12837)/1500 = 0.11
For <14000:
z = (14000 - 12837)/1500 = 0.78
P(0.11 < z < 0.78) = P(z < 0.78) - P(z < 0.11) = 0.7823 - 0.5438 = 0.2385
7.49% of the student makes more than $15,000, while 23.85% of the student makes between $13,000 and $14,000
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Zoe earns 22.50 per hour plus 3% commission on sales. last week she worked 34 hours and made sales totalling 15280. Calculate her pay for the week.
Answer: $1,223.40.
Step-by-step explanation:
Since she earns $22.5 per hour, for 34 hours, she would earn:
$22.5 × 34 = $765
She earn 3% of her sales, therefore find 3% of $15,280:
$15280(3%) = $15280(0.03) = $458.4
Add them together:
$765 + $458.4 = $1223.4
9514 1404 393
Answer:
$1,223.40
Step-by-step explanation:
Zoe's total pay is the sum of the products of hours and hourly rate, and sales and commission rate.
Pay = (34 h)($22.50/h) +($15,280)(.03) = $765.00 +458.40
Pay = $1,223.40
Zoe's pay for the week is $1,223.40.
The 90% confidence interval for the mean one-way commuting time in New York City is
5.22 < < 5.98 minutes. Construct a 95% confidence interval based on the same data.
Which interval provides more information?
Answer:
95% provides more information
Step-by-step explanation:
The confidence interval is obtained by using the relation :
Xbar ± Zcritical * σ/√n
(Xbar - (Zcritical * σ/√n)) = 5.22 - - - (1)
(Xbar + (Zcritical * σ/√n)) = 5.98 - - (2)
Adding (1) and (2)
2xbar = 5.22 + 5.98
2xbar = 11.2
xbar = 11.2 / 2 = 5.6
Margin of Error :
Xbar - lower C.I = Zcritical * σ/√n
Zcritical at 90% = 1.645
5.6 - 5.22 = 1.645 * (σ/√n)
0.38 = 1.645 * (σ/√n)
(σ/√n) = 0.38 / 1.645 = 0.231
Therefore, using the se parameters to construct at 95%
Zcritical at 95% = 1.96
Margin of Error = Zcritical * σ/√n
Margin of Error = 1.96 * 0.231 = 0.45276
C.I = xbar ± margin of error
C. I = 5.6 ± 0.45276
C.I = (5.6 - 0.45276) ; (5.6 + 0.45276)
C. I = (5.147 ; 6.053)
Hence, 95% confidence interval provides more information as it is wider.
The bell tower of the cathedral in Pisa, Italy, leans 5.6° from the vertical. A tourist stands 107 m from its base, with the tower leaning directly toward her. She measures the angle of elevation to the top of the tower to be 28.6°. Find the length of the tower to the nearest meter. m
Answer:
[tex]l=56m[/tex]
Step-by-step explanation:
From the question we are told that:
Angle from vertical [tex]\theta =5.6[/tex]
Horizontal Distance [tex]d=107m[/tex]
Angle of elevation [tex]\gamma=28.6[/tex]
Generally the Trigonometric equation for exterior angles is mathematically given by
[tex]Exterior\ angles=\sum of\ two\ interior\ angles[/tex]
Where
[tex]Exterior angles=90 \textdegree +5.6 \textdegree[/tex]
Therefore
[tex]90 \textdegree +\theta \textdegree=\omega+\gamma[/tex]
[tex]90 \textdegree +5.6 \textdegree=\omega+28.6 \textdegree[/tex]
[tex]\omega=67 \textdegree[/tex]
Generally the equation for The Sine rule is mathematically given by
[tex]\frac{sin \omega }{d}=\frac{sin \gamma}{l}[/tex]
[tex]l=\frac{107 sin 28.6}{sin 67 \textdegree }[/tex]
[tex]l=56m[/tex]
If a drug has a concentration of 8.22 mg per 3.039 mL, how many mL are needed to give 7.469 gram of the drug? Round to 1 decimal.
Answer:
2.8 litres
Step-by-step explanation:
8.22 mg per 3.039 mL
2.704 mg per 1 mL
7.469 gram = 7469 milligrams
7469 milligrams per 2,761.34927mL
= 2.761 litres = 2.8 litres
How to divided 245 by 70
Show your work
Answer:
Step-by-step explanation:
Hello!
2 4 5 ∟ 70
-2 1 3, 5
------------------------
3 5 0
3 5 0
- --------------------------------
0 0 0
I really need the help please and thank you
Asnwer: C
-------------------------------------
A veterinarian is visited by many pets and their owners each day. Before the doctor attends to each pet, an assistant records information including the type, age, weight, and height of each pet. What are the individuals in the data set?
[What are the individuals in the data set?]
pets
types
weights
heights
I think it's pets, just posting so it helps other people with it. Someone make sure in the answers though.
Answer:
pets bcos a vetenarian is a doctor for animals and tha question also says their owners.
Can someone please help me
Researchers would like to assess the overall health of white pine trees in a state park. Which of the following
methods for choosing the trees to assess would be considered a convenience sample?
O A ranger hires employees to assess every tree in the park.
O The 100 trees closest to a ranger station are assessed for damage.
O Agrid map of the park is used, and 100 random points on the grid are chosen and used to select the trees to
assess
O Each tree in the state park is tagged with a number, and 100 random numbers that represent the trees are
selected and assessed for damage.
Answer:
The 100 trees closest to a ranger station are assessed for damage.
Step-by-step explanation:
Convenience samples are samples taken from only around the focal point.
Option B is correct, The 100 trees closest to a ranger station are assessed for damage.
What is Statistics?Statistics is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data.
A convenience sample is a non-random method of sampling that involves selecting subjects that are easy to access or readily available.
Of the methods listed, the convenience sample is the one where the trees are selected based on their proximity to a ranger station:
The 100 trees closest to a ranger station are assessed for damage.
This method is a convenience sample because it does not involve random selection of trees.
Instead, the trees are chosen based on their proximity to a specific location.
This can introduce bias into the sample, as trees near the ranger station may not be representative of the overall health of white pine trees in the state park.
Hence, Option B is correct, The 100 trees closest to a ranger station are assessed for damage.
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The area of a rectangle is 63 ft^2, and the length of the rectangle is 11 ft more than twice the width. Find the dimensions of the rectangle.
What Is The Pythagorean Theorem?. ^ Means to the power of...
Answer:
I wish I knew that answer
Step-by-step explanation:
What is the area of a trapezoid.. base 14in and 7in height is 5in?
if the formula is [tex]\frac{(B+b)}{2} .h[/tex] we just need to plug in the values
21/2 = 10.5 x 5 = 52.5
hope it helps :)
Answer:
A = 52.5 in^2
Step-by-step explanation:
The area of a trapezoid is
A = 1/2 (b1+b2)h
where b1 and b2 are the bases and h is the height
A = 1/2 ( 14+7)*5
A = 105/2
A = 52.5 in^2
Which of the following equations is modeled by the graph?
A)
a = 50t
B)
a = 5t
C)
a = 50 + t
D)
a = 10t
Answer:
a = 50t
Step-by-step explanation:
A function is rise over run, or y/x.
In this graph, the rise (y) is the account balance, while the run (x) is time. To solve for the slope, or the "equation modeled by the graph," we need to divide the rise by the run.
The graph is shown in terms of (a, t). If we look at the first point, (50,1), the rise is 50 and the run is 1. 50/1 is 50. Therefore, a = 50t, since a = 50 and t = 1.
To check, we can try another point, (100, 2). The rise is 100 and the run is 2. Divide these together and you still get 50. You are multiplying the "t" value by 50 to get the "a" value.
Therefore, it's a = 50t
Find the quotient of 68.4 ÷ 18 = ________. Use an area model to help you solve. (this is on flvs by the way) answers:
3.3
3.5
3.8
3.9
Answer:
C
Step-by-step explanation:
3.8 is the answer
68.4÷18=3.8
HELLO PLEASE HELP??
which equation represents the circle described? 1. the radius is 2 units 2. the center of the circle is at (5,-6) (x+5)^2+ (y- 6)^2 =4
(x - 5)^2 + ( y + 6)^2 = 4
(x + 5)^2 + (y - 6)^2 =2
(x - 5)^2 + (y + 6)^2 =2
Answer:
(x-5)^2 + (y+6)^2 = 4
Step-by-step explanation:
The equation of a circle is given by
(x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center and r is the radius
(x-5)^2 + (y- -6)^2 = 2^2
(x-5)^2 + (y+6)^2 = 4
Please explain the answer
Answer:
3.5
Step-by-step explanation:
in order to find the maximum, we are basically solving to find the vertex of the graph. to find the vertex use :
-b/2a
the 'b' is 112
the 'a' is -16
so :
-112/-32 = 3.5
the answer is B, 3.5
The lengths of pregnancies in a small rural village are normally distributed with a mean of 264.1 days and a standard deviation of 12.9 days. In what range would you expect to find the middle 95% of most pregnancies
Answer:
The range of the 95% data (X) = 238.3 days < X < 289.9 days
Step-by-step explanation:
Given;
mean of the normal distribution, m = 264.1 days
standard deviation, d = 12.9 days
between two standard deviation below and above the mean is 96% of all the data.
two standard deviation below the mean = m - 2d
= 264.1 - 2(12.9)
= 238.3 days
two standard deviation above the mean = m + 2d
= 264.1 + 2(12.9)
= 289.9 days
The middle of the 95% of most pregnancies would be found in the following range;
238.3 days < X < 289.9 days
From the figure, the cylinder glass has a height of 6 inches and a radius of the mouth of the glass 1.25 inches. Find the length of SK in inches.
Answer:
D. 6.5
Step-by-step explanation:
The diameter of the cylinder is 1.25 x 2 = 2.5
SK = √1.25² + 6² = √42.25 = 6.5
HELP NEEDED PLEASE!!!
Answer:
B - They are symmetric over the y-axis
Step-by-step explanation:
A - I couldn't find a way to explain this one
B - Even functions have graph symmetry across the y-axis, I'm not sure if you looking for multiple answers, but I got B as one of them.
C - An odd function has rotational symmetry, and even function has reflects
D - An even function is symmetric over the y-axis not the x-axis
Kara ate 2 7/9 of the raisins she packed. Which box shows the decimal equivalent of the amount of raisins she ate? Box A: 2.777 etc Box B: 2.79 Box C: 2.999 etc.
Answer: Box A, 2.777
=======================================================
Explanation:
When using a calculator or long division, you should find that
7/9 = 0.7777...
where the 7s go on forever
So we can say that 7/9 = 0.777 approximately. You could argue that the last '7' would round up to an '8' and we could say 7/9 = 0.778; however, I'll stick to the first value so that it matches with the answer.
Since 7/9 = 0.777, this means 2 & 7/9 = 2 + 7/9 = 2 + 0.777 = 2.777 which is box A.
Answer:
A
Step-by-step explanation:
What fraction is equivalent to eight tentHs
write 11.4 in standard form
[tex]11.4[/tex]
[tex] \to \: 1.14 \times {10}^{1} [/tex]
Adam runs 13 miles in 143 minutes. How many minutes does it take him to run one mile? Adam runs at a rate of minutes per mile.
Answer:
Adam runs at a rate of 11 minutes per mile.
Step-by-step explanation:
Take 143 minutes and divide by 13 miles and you will get the answer of 11 minutes.
PLEASE MARK ME BRAINEIST.
Answer:
it would take him 11 minuets to run a mile
Step-by-step
143 divided by 13 is 11 which means each mile takes 11
you can also check the answer by multiplying 13 times 11 which is 143
I need help ASAP anyone?
Explanation:
Each vertical asymptote is due to a division by zero error.
For instance, the vertical asymptote x = 3 is from the factor (x-3) in the denominator. If we plugged x = 3 into (x-3), then it turns into 0 and we cannot have 0 in the denominator.
Similarly, the factor (x+3) leads to x = -3
So overall, we have (x-3)(x+3) in the denominator.
Help me please, is it d?
Answer:
Yes D is the correct answer :)
Answer:
Yes, D
Step-by-step explanation:
State and prove the converse of the pythagorean theorem using a two-column proof
Answer:
Step-by-step explanation:
I'm from the UK and I'm not familiar with a two column proof, but the following proves the converse.
Draw 2 right angled triangles with the 2 legs = a and b in each case and the longest side = c in one triangle and f in the other.
By Pythagoras a^2 + b^2 = c^2 (Given)
Also in the other triangle a^2 + b^2 = f^2, if it is right-angled.
Therefore a^2 = f^2 and a = f.
So the 2 triangles are congruent by SSS.
So m < C in one triangle = m < F ( the angles opposite the hypotenuse)
Therefore the second triangle is right angled .
This completes the proof.
If it takes sally 45 minutes to walk 1 mile how long will it take sally to walk 1,954 miles?
Answer:
87,930 Minutes
Step-by-step explanation:
Let us use unit rates for this question. Let's first draw a table.
Minutes Mile
45 1
This table represents the relation of Sally walking 1 mile in 45 minutes. Let's put the other data we know of in the table.
Minutes Mile
45 1
1954
To find the number of minutes, we must know that if 1 mile takes 45 minutes, we must multiply the number of minutes, which is 45, by 1954 to get the result desired. Let us do that.
1954*45 = 87,930
Minutes Miles
45 1
87,930 1954
Therefore it will take Sally 87,930 minutes to walk 1,954 Miles.
I Hope This Helps!
Please Mark Brainliest!
Write the ratio as a fraction in simplest form
4.5 hr to 4 hr
9514 1404 393
Answer:
9/8
Step-by-step explanation:
To clear the fraction in the ratio 4.5 to 4, you can multiply both numbers by 2. This gives you the reduced ratio 9 to 8. As a fraction, that is 9/8.
A random sample of 25 graduates of four-year business colleges by the American Bankers Association revealed a mean amount owed in student loans was $14,381 with a standard deviation of $1,892. Assuming the pop is normally distributed:
a) Compute a 90% confidence interval, as well as the margin of error.
b) Interpret the confidence interval you have computed.
Answer:
a) The 90% confidence interval for the mean amount owed in student loans of graduates of four-year business colleges is ($13,600, $15,162), having a margin of error of $781.
b) We are 90% sure that the mean amount owed in student loans of graduates of all four-year business colleges is between $13,600 and $15,162.
Step-by-step explanation:
Question a:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So
df = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 2.0639
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.0639\frac{1892}{\sqrt{25}} = 781[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 14381 - 781 = $13,600
The upper end of the interval is the sample mean added to M. So it is 14381 + 781 = $15,162
The 90% confidence interval for the mean amount owed in student loans of graduates of four-year business colleges is ($13,600, $15,162), having a margin of error of $781.
b) Interpret the confidence interval you have computed.
We are 90% sure that the mean amount owed in student loans of graduates of all four-year business colleges is between $13,600 and $15,162.
