Answer:
B. Cluster
Step-by-step explanation:
Samples may be classified as:
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Each Continental Airlines flight is a group.
30 of them are chosen, and in each group chosen, every passenger is surveyed.
So cluster sampling was used.
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
B. 4x² - 20x + 26
Step-by-step explanation:
→Set it up, like so:
(2x - 5)² + 1
4x² - 20x + 25 + 1
→Add like terms (25 and 1):
4x² - 20x + 26
2(x+3)+5 simplified expression
Answer:
2x+11
Step-by-step explanation:
2(x+3)+5
Distribute
2x+ 6 +5
Combine like terms
2x+11
Answer:
2x + 11
Step-by-step explanation:
First distribute 2 to the x + 3
2x + 6 + 5
Combine the constants
6+5=11
2x + 11
The simplified expression is 2x + 11
Which statement about the two-way frequency table is true?
Answer:
Which statements?
Step-by-step explanation:
Can you write the statements please?
Suppose you
earn $10.30 per hour and work 24 eight-hour
days in a month. How much do you earn in that month?
Answer:1977.60
Step-by-step explanation:
24x8= 192
192x 10.30= 1977.60
You are situated 300 feet from the base of Tower Glitz Plaza watching an external elevator descend down the side of the building. At a certain instant the elevator is 500 feet away from you, and its distance from you is decreasing at a rate of 16 ft/sec. How fast is the elevator descending at that instant?
Answer:
18.66 ft/s
Step-by-step explanation:
The distance between you and the elevator is given by:
[tex]h=\sqrt{x^2+y^2}[/tex]
The rate of change for the distance between you and the elevator is given by:
[tex]\frac{dh}{dt}=\frac{dh}{dy}*\frac{dy}{dt}[/tex]
[tex]-16=\frac{dh}{dy}*\frac{dy}{dt}[/tex]
[tex]\frac{dh}{dy}=\frac{d}{dy} (\sqrt{x^2+y^2})\\[/tex]
Applying the chain rule:
[tex]u=x^2+y^2\\\frac{dh}{dy}=\frac{d\sqrt u}{du} *\frac{du}{dy}\\\frac{dh}{dy}=\frac{1}{2\sqrt u} *2y\\\frac{dh}{dy}=\frac{y}{\sqrt {(x^2+y^2)}}[/tex]
Therefore, at x=300 and y = 500, dy/dt is:
[tex]-16=\frac{y}{\sqrt {(x^2+y^2)}}*\frac{dy}{dt}\\-16=\frac{500}{\sqrt {(300^2+500^2)}}*\frac{dy}{dt}\\\frac{dy}{dt}=-18.66\ ft/s[/tex]
The elevator is descending at 18.66 ft/s.
Which equation does not represent a linear function of x?
a. y = -3 over 4 x
b. y = x over 2
c. y = - 3 + 2x
d. y = 3x2 - 2
In order to get toys from under the couch, Mom lifted up the couch to an angle of 31 degrees. The kids still could not reach the toys. Then, she lifted it up another 15 degrees, and the kids pulled out a bouncy ball, a foam dart, three rubber bands, and a Lego. What was the measure of the total angle Mom lifted the couch?
Answer:
46 degrees
Step-by-step explanation:
Add 31 + 15 together to find the total angle
31 + 15 = 46
= 46 degrees
Answer:
That is 46°.
Step-by-step explanation:
31 + 15 = 46
So, 46°.
The width of the rectangle is 2 more than the length. The area of the rectangle is 63 square inches. How long is the width?
Answer:
9 inches
Step-by-step explanation:
Area of rectangle= length ×width
Let the length of the rectangle be x inches.
Width of rectangle= (x +2) inches
since the width is 2 more than the length.
63= x(x+2)
63= x(x) +2x
Bringing constant to one side,
x² +2x -63= 0
(x +9)(x-7) = 0 (factorise)
x+9= 0 or x-7= 0
x= -9 or x= 7
(reject)
width of rectangle
= 7+2
= 9 inches
*We reject x= -9 since the length of the rectangle cannot be a negative number.
Solve the following system of equations using the elimination method. 5x – 5y = 10 6x – 4y = 4
Answer:
11×-9y=14
Step-by-step explanation:
123hsvwjwjbe
Answer:
(-2,-4)
Step-by-step explanation:
add the equations in order to solve the first variable. put the value into the other equations in order to solve the other variables.
A research scientist wants to know how many times per hour a certain strand of bacteria reproduces. The mean is found to be 7.8 reproductions and the population standard deviation is known to be 2.2. If a sample of 697 was used for the study, construct the 85% confidence interval for the true mean number of reproductions per hour for the bacteria. Round your answers to one decimal place.
Answer:
The 85% confidence interval is ( 7.7 , 8.0 )
Step-by-step explanation:
In order to find the 85% confidence interval you use the following formula:
[tex]\overline{x}\pm Z_{\alpha/2}\frac{\sigma}{\sqrt{n}}[/tex] (1)
where
[tex]\overline{x}[/tex]: mean of number of bacteria reproduces per hour = 7.8
σ: standard deviation = 2.2
n: sample size = 967
α: 1 - 0.85 = 0.15
Zα/2: Z factor of the density distribution = 1.44
You replace the values of all parameters in the equation (1):
[tex]7.8\pm (1.44)\frac{2.2}{\sqrt{697}}\\\\7.8\pm0.119\\\\[/tex]
Then, the confidence interval is:
[tex](7.8-0.119,7.8+0.119)\\\\(7.7,8.0)[/tex]
An aeroplane X whose average speed is 50°km/hr leaves kano airport at 7.00am and travels for 2 hours on a bearing 050°. It then changes its course and flies on a bearing 1200 to an airstrip A. Another aeroplane Y leaves kano airport at 10.00am and flies on a straight course to the airstrip A. both planes arrives at the airstrip A at 11.30am. calculate the average speed of Y to three significant figures. the direction of flight Y to the nearest degree
Answer:
(a)123 km/hr
(b)39 degrees
Step-by-step explanation:
Plane X with an average speed of 50km/hr travels for 2 hours from T (Kano Airport) to point U in the diagram.
Distance = Speed X Time
Therefore: Distance from T to U =50km/hr X 2 hr =100 km
It moves from Point U at 9.00 am and arrives at the airstrip A by 11.30am.
Distance, UA=50km/hr X 2.5 hr =125 km
Using alternate angles in the diagram:
[tex]\angle U=110^\circ[/tex]
(a)First, we calculate the distance traveled, TA by plane Y.
Using Cosine rule
[tex]u^2=t^2+a^2-2ta\cos U\\u^2=100^2+125^2-2(100)(125)\cos 110^\circ\\u^2=34175.50\\u=184.87$ km[/tex]
Plane Y leaves kano airport at 10.00am and arrives at 11.30am
Time taken =1.5 hour
Therefore:
Average Speed of Y
[tex]=184.87 \div 1.5\\=123.25$ km/hr\\\approx 123$ km/hr (correct to three significant figures)[/tex]
b)Flight Direction of Y
Using Law of Sines
[tex]\dfrac{t}{\sin T} =\dfrac{u}{\sin U}\\\dfrac{125}{\sin T} =\dfrac{184.87}{\sin 110}\\123 \times \sin T=125 \times \sin 110\\\sin T=(125 \times \sin 110) \div 184.87\\T=\arcsin [(125 \times \sin 110) \div 184.87]\\T=39^\circ $ (to the nearest degree)[/tex]
The direction of flight Y to the nearest degree is 39 degrees.
Thw sum of 12x^2+9x^2
Answer:
21 x^2
Step-by-step explanation:
12x^2+9x^2
Combine like terms
x^2(12+9)
x^2(21)
21 x^2
y - 15=x Solve for Y
Answer:
y = x+15
Step-by-step explanation:
y - 15=x
Add 15 to each side
y - 15+15=x+15
y = x+15
Answer:
[tex]y=x+15[/tex]
Step-by-step explanation:
[tex]y - 15=x[/tex]
Add [tex]15[/tex] on both sides of the equation.
[tex]y - 15+15=x+15[/tex]
The [tex]y[/tex] should be isolated on one side of the equation.
[tex]y=x+15[/tex]
what the product of the reciprocals of 2/3, 1/8, and 5
Answer:
12/5
Step-by-step explanation:
Reciprocal of 2/3 is 3/2
Reciprocal of 1/8 is 8/1
Reciprocal of 5 is 1/5
[tex]\frac{3}{2} \times \frac{8}{1} \times\frac{1}{5} = \frac{24}{10} \\[/tex]
Can be simplified to
[tex]\frac{12}{5}[/tex]
help asap, will get branliest !!
Answer:
D
Step-by-step explanation:
Lines EF and GH are already parallel. Translating them 2 units to the side without changing how far apart they are vertically means they won't intersect and will remain the same distance apart.
Answer:
D
Step-by-step explanation:
They are parallel lines
Makeeya only has $25 to spend on a custom T-shirt. It costs $10 for a plain T-shirt, and there is a charge of $$1.50 for each square inch of design added to the T-shirt. Which solution represents the number of square inches of design,x , Makeeya can put on her T-shirt?
Answer:
10 square inches
Step-by-step explanation:
cost of a plain t-shirt = $10
cost of 1 square inch of design addition = $1.50
let there be x square inches of design
then cost of x square inches of design = x*cost of 1 square inch of design
= 1.50*x = 1.5x
Total cost for t-shirt with x square inches of design = cost of a plain t-shirt + cost of x square inches of design = 10 + 1.5 x
It is given that Makeeya has only $25, then total cost which can be afforded by him will be $25 only
Thus,
10 + 1.5 x = 25
=> 1.5x = 25-10 = 15
=> x = 15/1.5 = 10
Thus, Makeeya can put 10 square inches of design on her T-shirt.
Find the distance between the pair of points: (9,−3) and (0,−10).
Answer:
√130 is the distance between (9,-3) (0,-10)
Rebecca Pearson is a widow and needs to take care of the expenses in her household. Her budget is below.
Find her net monthly cash flow. (Assume 1 month = 4 weeks)
Income Expenses
Salary: $2300/month
Rent: $1090/month
Groceries: $200/week
Utilities: $125/month
Car Insurance: $525 semiannually
Gasoline: $25/week
Miscellaneous: $200/month
Phone: $50/month
Hey there!
First, let's take all of the expenses and change the ones that aren't monthly into monthly.
Groceries: $800/month
Car insurance: $87.5/month
Gasoline: $100/month
Now, let's add together all of our expenses
1090+800+125+87.5+100+200+50=2452.5
Now, we subtract that from her salary.
2300-2452.5=-152.5
Therefore, Rebecca's net monthly cash flow is -$152.5. She should spend a bit less on groceries, not do so much miscellaneous, find a place that charges less rent, drive less, etc. so she isn't spending more than she earns.
I hope that this helps! Have a wonderful day!
Please answer this correctly
Answer:
4 pizza recipes
Step-by-step explanation:
It shows 4 Xs after the [tex]\frac{3}{4}[/tex] mark. So there are 4 recipes that use MORE than [tex]\frac{3}{4}[/tex] cups of cheese.
Answer:
4 cups of cheese
Step-by-step explanation:
More than 3/4 are (3+1) = 4 cups of cheese
Mark Wishing the Brainliest because he deserves it :)
One number is 3 more than 2 times the other, and their sum is 27. Find the numbers.
If x represents the smaller number, then the larger number is
3x + 2
2x + 3
21x + 3)
Answer:
Option 2 is correct
Step-by-step explanation:
One number is 2 times another number plus 3. Their sum is 21.
"One number is 2 times another number plus 3" translated to
x = smaller number = another number
It is also given that: Their sum is 21.
Combine like terms:
3x+3 = 21
Answer:
I do questions like these everyday so I have too much experience. Let me explain step by step for you.
Brainliest?
First lets set 2 variables x and y
Lets make 2 equations.
x=3+2*y
Thats because it says 'x' is 3 more (+) than 2 times(*) 'y'
Now lets set second, we know both of them add up to 27.
x+y = 27
Since we know what x is equal to (look above equation)
We can replace it.
x is replaced with 3+2*y
3+2y+y = 27
3+4y = 27
Simplify 27-3 = 24
24/4 = 6
Now lets plug in for x
3+2*6 = 15
15 - x
6 - y
:))
Los Angeles workers have an average commute of 33 minutes. Suppose the LA commute time is normally distributed with a standard deviation of 15 minutes. Let X represent the commute time for a randomly selected LA worker. Round all answers to 4 decimal places where possible.
a. What is the distribution of X? X N
b. Find the probability that a randomly selected LA worker has a commute that is longer than 38 minutes
c. Find the 80th percentile for the commute time of LA workers. _______ minutes
Answer:
a) N(33,15).
b) 37.33% probability that a randomly selected LA worker has a commute that is longer than 38 minutes
c) 45.6 minutes.
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 = 15[/tex]
a. What is the distribution of X?
Normal with mean 33 and standard deviaton 15. So
N(33,15).
b. Find the probability that a randomly selected LA worker has a commute that is longer than 38 minutes
This is 1 subtracted by the pvalue of Z when X = 38. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{38 - 33}{15}[/tex]
[tex]Z = 0.333[/tex]
[tex]Z = 0.333[/tex] has a pvalue of 0.6267.
1 - 0.6267 = 0.3733
37.33% probability that a randomly selected LA worker has a commute that is longer than 38 minutes
c. Find the 80th percentile for the commute time of LA workers.
This is X when Z has a pvalue of 0.8. So it is X when Z = 0.84.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.84 = \frac{X - 33}{15}[/tex]
[tex]X - 33 = 0.84*15[/tex]
[tex]X = 45.6[/tex]
45.6 minutes.
What is the equation of the following line? Be sure to scroll down first to see all answer options.(0,0)(4,-2)
Answer:
i hope this helps you
The Equation of the line is 2y = -x.
What is the equation of a line passing through two given points in 2 dimensional plane?Suppose the given points are (x_1, y_1) and (x_2, y_2), then the equation of the straight line joining both two points is given by
[tex](y - y_1) = \dfrac{y_2 - y_1}{x_2 - x_1} (x -x_1)[/tex]
Given Points of the line are (0,0) and (4,-2).
Since we are given two points.
[tex](y - y_1) = \dfrac{y_2 - y_1}{x_2 - x_1} (x -x_1)\\\\\\(y - (-2)) = \dfrac{-2- 0}{4 - 0} (x -4)\\\\\\(y - (-2)) = \dfrac{-1}{2} (x -4)\\\\2(y + 2) =-1(x -4)\\\\2y + 4 = -x + 4\\\\2y = -x\\\\[/tex]
Therefore, Equation of the line is 2y = -x.
Learn more about linear equations here:
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A large software company gives job applicants a test of programming ability and the mean for that test has been 160 in the past. Twenty-five job applicants are randomly selected from a large university and they produce a mean score of 183 with a standard deviation of 12. Use a 0.05 level of significance to test whether the mean score for students from this university is greater than 160. use the P-value method of testing hypotheses.
Answer:
[tex]t=\frac{183-160}{\frac{12}{\sqrt{25}}}=9.58[/tex]
The degrees of freedom are given by:
[tex]df=n-1=25-1=24[/tex]
And the p value would be:
[tex]p_v =P(t_{(24)}>9.58)\approx 0[/tex]
Since the p value is very low at any significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 160
Step-by-step explanation:
Information provided
[tex]\bar X=183[/tex] represent the sample mean
[tex]s=12[/tex] represent the sample standard deviation
[tex]n=25[/tex] sample size
[tex]\mu_o =160[/tex] represent the value to test
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
Hypothesis to test
We want to verify if the true mean is greater than 160, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 160[/tex]
Alternative hypothesis:[tex]\mu > 160[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info we got:
[tex]t=\frac{183-160}{\frac{12}{\sqrt{25}}}=9.58[/tex]
The degrees of freedom are given by:
[tex]df=n-1=25-1=24[/tex]
And the p value would be:
[tex]p_v =P(t_{(24)}>9.58)\approx 0[/tex]
Since the p value is very low at any significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 160
find the circumference of the circle use 3.14 for pi when the radius is 13 cm
Answer:
C =81.64 cm
Step-by-step explanation:
The circumference of a circle is given by
C = 2*pi*r
C = 2 * 3.14 * 13
C =81.64 cm
_______________________________
Radius(r)=13 cm
Circumference of circle=?
Now,
Circumference of circle=2 pi r
=2*3.14*13
=81.64 cm
Hope it helps..
Good luck on your assignment
________________________________
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
D. It would be less steep.
Step-by-step explanation:
→When the absolute value of the number in front of x is greater than 1, the function on the graph narrows. When the absolute value of the number in front of x is less than 1, the function on the graph widens.
In this case, the number is less than 1, making it grow wider. And as a result of it growing wider, it also becomes less steep.
Simplify: 5y + 2p – 4y – 6P
Answer:
[tex]y-4p[/tex]
Step-by-step explanation:
Add/subtract like terms.
[tex]5y+2p-4y-6p\\5y-4y+2p-6p\\y-4p[/tex]
Find the SURFACE AREA of this composite solid.
FINDING THE SURFACE AREA OF A COMPOSITE SOLID
About "Finding the surface area of a composite solid"
Finding the surface area of a composite solid :
A composite solid is made up of two or more solid figures.
To find the surface area of a composite solid, find the surface area of each figure. Subtract any area not on the surface.
Finding the surface area of a composite solid - Examples
Example 1 :
Daniel built the birdhouse shown below. What was the surface area of the birdhouse before the hole was drilled ?
Solution :
Step 1 :
Identify the important information.
• The top is a triangular prism with h = 24 cm. The base is a triangle with height 8 cm and base 30 cm.
• The bottom is a rectangular prism with h = 18 cm. The base is a 30 cm by 24 cm rectangle.
• One face of each prism is not on the surface of the figure.
Step 2 :
Find the surface area of each prism.
Add the areas. Subtract the areas of the parts not on the surface.
Step 3 :
Find the area of the triangular prism.
Perimeter = 17 + 17 + 30 = 64 cm
Base area = (1/2)(30)(8) = 120 sq.cm
Surface area = Ph + 2B
Surface area = 64(24) + 2(120)
Surface area = 1,776 sq.cm
Step 4 :
Find the area of the rectangular prism.
Perimeter = 2(30) + 2(24) = 108 cm
Base area = 30(24) = 720 sq.cm
Surface area = Ph + 2B
Surface area = 108(18) + 2(720)
Surface area = 3,384 sq.cm
Step 5 :
Add. Then subtract twice the areas of the parts not on the surface.
Surface area = 1,776 + 3,384 - 2(720) = 3,720 sq.cm
The surface area before the hole was drilled was 3,720 sq.cm.
The surface area before the hole was drilled was; 3,720 sq.cm.
What is composite solid?A composite solid is made up of two or more solid figures.
To determine the surface area of a composite solid, find the surface area of each figure. Subtract any area not on the surface.
Given that the top is a triangular prism with h = 24 cm. The base is a triangle with height 8 cm and base 30 cm.
The bottom is a rectangular prism with h = 18 cm.
The base is a 30 cm x 24 cm rectangle.
One face of each prism is not on the surface of the figure.
Then the surface area of each prism.
Add the areas. Subtract the areas of the parts not on the surface.
The area of the triangular prism.
Perimeter = 17 + 17 + 30 = 64 cm
Base area = (1/2)(30)(8) = 120 sq.cm
Surface area = Ph + 2B
Surface area = 64(24) + 2(120)
Surface area = 1,776 sq.cm
Now the area of the rectangular prism.
Perimeter = 2(30) + 2(24) = 108 cm
Base area = 30(24) = 720 sq.cm
Surface area = Ph + 2B
Surface area = 108(18) + 2(720)
Surface area = 3,384 sq.cm
Now,
Surface area = 1,776 + 3,384 - 2(720) = 3,720 sq.cm
Learn more about the area;
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Simplify
6x^-2. ....
Answer:
6/x^2
Step-by-step explanation:
6x^-2
6*x^-2
6*(1/x^2)
6/x^2
Steve drove for 812 hours at 72 miles per hour. How much distance did he travel
Answer:
[tex]58,464 \: \: miles[/tex]
Step-by-step explanation:
[tex]speed = \frac{distantce}{time} \\ [/tex]
[tex]distance = speed \times time \\ x = 72 \times 812 \\ x = 58,464 \: \: miles[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
Ann pays $300 for membership to a local gym. She is allowed to bring one guest on any visit. John pays Ann $5 to go to the gym with her occasionally. Describe what the expression 300 - 5t could represent. Then evaluate the expression for T equals five 10 15 and 20
Answer:
f
Step-by-step explanation:
