A large school district claims that 80% of the children are from low-income families. 150 children from the district are chosen to participate in a community project. Of the 150 only 70% are from low-income families. The children were supposed to be randomly selected. Do you think they really were

Answers

Answer 1

Incomplete question. However, I answered from a general research perspective.

Explanation:

Note, the term sample used in statistical research refers to subjects or persons carefully selected (using a particular sampling method/type ) to represent the target population.

A randomly selected sample could be done as either:

Simple Random Sampling Stratified Random Sampling Cluster Random Sampling.Systematic Random Sampling.

Using any of the above sampling methods could result in 70% of the population being from low-income families as this is a matter of chance. Hence, we can agree with the research results.

Answer 2

Using the z-distribution, it is found that since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the children were not randomly selected.

At the null hypothesis, we test if they were really randomly selected, that is, the proportion is of 80%:

[tex]H_0: p = 0.8[/tex]

At the alternative hypothesis, we test if they were not randomly selected, that is, the proportion is of less than 80%.

[tex]H_1: p < 0.8[/tex]

The test statistic is given by:

[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

In which:

[tex]\overline{p}[/tex] is the sample proportion. p is the proportion tested at the null hypothesis. n is the sample size.

For this problem, the parameters are:

[tex]p = 0.8, n = 150, \overline{p} = 0.7[/tex]

Then, the value of the test statistic is:

[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

[tex]z = \frac{0.7 - 0.8}{\sqrt{\frac{0.8(0.2)}{150}}}[/tex]

[tex]z = -3.06[/tex]

The critical value for a left-tailed test, as we are testing if the proportion is less than a value, with a significance level of 0.05, is of [tex]z^{\ast} = -1.645[/tex].

Since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the children were not randomly selected.

A similar problem is given at https://brainly.com/question/24166849


Related Questions

A toy has been marked up by 75%. The tag lists the price as $63. Find the wholesale price.

Answers

Answer:

110.25

Step-by-step explanation:

You do 1.75 because it is a mark up and ur paying 175 percent

Brandon's car used 3/4 of a gallon to travel 13 1/2 miles. How many miles can the car go
on one gallon of gas?

Answers

Answer:

12

Step-by-step explanation:

Answer:

Brandon's car can go in one gallon gas= 18 miles

Step-by-step explanation:Definition of gallon

In the United States, the gallon is a unit of measurement for liquids such as gasoline, water, and milk. If your car's tank is nearly empty, you should stop and purchase at least a few additional gallons of gas. A gallon of liquid is equal to 4 quarts or 3.785 liters.

Brandon's car used 3/4 of a gallon to travel 13 1/2 miles.

3/4 of a gallon(G)= 13 1/2 miles

3/4*G=27/2

G=18 miles

Hence, Brandon's car can go in one gallon gas= 18 miles.

To know more about it

https://brainly.com/question/23165699

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Diameter of a circle is 5 what is the area in simplest form

Answers

Answer:

19.6 cm²

Step-by-step explanation:

The formula of the area of a circle

= πr²

The radius of the circle

= 5÷2

= 2.5 cm

The area of the circle

= π×2.5²

= 19.63495...

= 19.6 cm² (rounded to the nearest tenth)

What is the median of 1, 3, 6, 8, 9, 9
Answer choices: A. 6
B. 7
C. 8
D. 9

Answers

Answer:

B

Step-by-step explanation:

The median is the middle value of the data arranged in ascending order. If there is no exact middle value then it is the average of the values either side of the middle.

1,  3,  6,  8,  9,  9

           ↑ middle

median = [tex]\frac{6+8}{2}[/tex] = [tex]\frac{14}{2}[/tex] = 7 → B

Answer:

B. 7

Step-by-step explanation:

(6 + 8) ÷ 2 = 7

I hope this is right if its not im sorry

(4) A sign on the road says: "Speed limit, 60 mph." Let s be the speed of a car. Choose the correct inequality that matches the information on the sign. the answers are= s<60 , s=60 , s<60 , s>60​

Answers

Step-by-step explanation:

Choose the correct inequality that matches the information on the sign. the answers are

s<60

Draw a line representing the "rise" and a line representing the "run" of the line. State
the slope of the line in simplest form.
Click twice to plot each segment.
Click a segment to delete it.


Answers

I can't plot it for you, but the slope will be the y/x or the rise/run.

You can find the slope by using 2 points of the line and subtracting the (y1-y2)/(x2-x1)

slo
[tex] {e}^{4 - 7x} + 11 = 20[/tex]
ve ​

Answers

Answer:

x is about 0.26

Step-by-step explanation:

[tex]e^{4-7x}+11=20[/tex]

[tex]e^{4-7x}=9[/tex]

[tex]ln(e^{4-7x})=ln(9)[/tex]

[tex]4-7x=ln(9)[/tex]

[tex]-7x=ln(9)-4[/tex]

[tex]x=\frac{ln(9)}{-7} +\frac{4}{7}[/tex]

[tex]x=\frac{4-ln(9)}{7}[/tex]

[tex]x=0.2575393461[/tex]

PLZ RESPOND AS SOON AS POSSIBLE
What point is located at (-2, -6)
a. F
b. G
c. H
d. K

Answers

Answer:

Can we get an image of the graph

Step-by-step explanation:

Where is the graph?BTW, that point is located in quadrant III

If anyone can help me I’d appreciate it, geometry is messing me up a bit

Answers

Answer:

A) It is right

Step-by-step explanation:

∠A=∠C, because a 180° line (straight line) meats at a certain point reaching the edge, which then means that the angles of 'A' and 'C' have to be the same.

So ∠A= 45°, and ∠C= 45°.

45+45= 90

A triangle's angles add to 180°.

180-90=90

∴∠B=90°, making it a right-angled triangle.

Determine the center and radius of the following circle equation: x ^ 2 + y ^ 2 - 6x + 2y - 39 = 0

Answers

x^2-6x+y^2+2y-39=0 =(x-3)^2 -9 + (y+1)^2 -1-39=0 so (x-3)^2 + (y+1)^2 = 49 . The center is at (3,-1) and the radius is 7 units.

Find the area of each figure. Use 3.14 for pi

Answers

the area of the rectangle is 128 ft. the area of the triangle is 12ft. together, it’s 140 ft.

¿Cuánto es el interés simple de $800.00 al 3.5 % durante un año? ​

Answers

Answer:

$28

Step-by-step explanation:

given that

The Principal amount is $800

The rate of interest is 3.5%

And, the time period is one year

we need to find out the simple interest

As we know that

Simple interest = Principal × rate × time period

= $800 × 3.5% × 1 year

= $28

hence, the simple interest is $28

For a quadratic equation where: 2++=0
a
x
2
+
b
x
+
c
=
0

Where: 2−4<0
b
2

4
a
c
<
0

How many solutions do you have?

State whether the solutions are rational, irrational, or non-real. Explain why.

Answers

Answer: No real solution

Step-by-step explanation:

Given

For the quadratic equation

[tex]ax^2+bx+c=0[/tex]

It is given that [tex]b^2-4ac<0[/tex]

[tex]D=b^2-4ac[/tex]

If [tex]D=0[/tex] roots are real and equal

If [tex]D>0[/tex] roots are real and distinct

If [tex]D<0[/tex] roots are imaginary

In this case, [tex]D<0[/tex]

So, there is no real solution for the given quadratic equation.

2. 6t - 12=48 3. 85*4=100​

Answers

Answer:

2 ) 6t=48+12

t=60/6

t=10

A magazine subscription runs several promotions. Customers can choose from the following deals:
Option A: 15% off an annual subscription of $86
Option B: pay $6.50 per month
How much will a customer save by purchasing the annual subscription overpaying per month?

Answers

1.8461 diveded 12/86

How old is the youngest employee

Answers

Answer:

10

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

It doesn't show the exact ages. The answer would be "10-19", but there is no choice for that. Therefore, the answer cannot be determined because we don't have the exact age.

:D

What is the total area, in square centimeters, of the shaded sections of the trapezoid
below?
4.2 cm
7.2 cm
6.1 cm
8 cm
2
cm
Answer: A=

Answers

uhh file explication

Answer:

A=34.77 cm^2

Step-by-step explanation:

At the party, Max wants each balloon to
have a string that is 100 centimeters long.
The string he wants to buy comes in rolls of
25 meters. How many rolls of string does
Max need to buy if he plans to have 50
balloons at the party?
Hellp me with this

Answers

Max needs to buy two rolls of string, hopefully this helped :)

The graph shows the amount of petrol used, in litres, against distance travelled in miles.
How many litres of petrol are used to travel 39 miles?

Answers

Answer:

Step-by-step explanation:

Each mile on the y axis is represented by the length of 1 square.Each 1/10 of a liter is represented by the width of 1 square.So you go 1 square down from 40.Travel across until you hit the red lineGo down and read the answer on the x axis.I get 2.6

So to travel 39 miles, you must use 2.6 Liters of fuel.

Instructions: Use the ratio of a 45-45-90 triangle to solve for the variables. Leave your answers as radicals in simplest form.

Answers

Answer:n

Step-by-step explanationaa:

ABCD is a square and it's side is 16 cm long. What is the area of the shaded part?​

Answers

Answer:

I'm sorry I can't help because I don't know what part is shaded.  Note: Since a square has the same length for each side all the sides are 16 cm.

Area and Perimeter for WHOLE square:

A: 256 sq cm

P: 64 cm

Solve for g. Show your work!

g + 7 - 4 = 15

Answers

Answer:

g = 12

Step-by-step explanation:

First, simplify by subtracting 4 from 7:

g + 7 - 4 = 15

g + 3 = 15

Solve for g by subtracting 3 from both sides:

g = 12

So, the answer is g = 12

Simplify by subtracting 4 from 7:

g + 7 - 4 = 15

g + 3 = 15

Solve for g by subtracting 3 from both sides:

g = 12

 answer is g = 12

Sebastian says that the graph below shows the solution set of the inequality 2.5x≥−20. Do you agree?

Answers

Answer:

There is not a graph.

Step-by-step explanation:

You forgot to include the screenshots.

A study published in Psychiatry Research states that 62% of autistic children are left-handed.[12]

A local resource for children with autism, Central Coast Autism Learning Partners, is curious to see
if their set of autistic children show a similar proportion of being left-handed. When a random
sample of 26 autistic children were observed, 17 were found to be left-handed. Is there enough
statistical evidence based on the sample to dispute the results of the study published in Psychiatry
Research? Use the P-value method and let
a=.05.

Answers

Answer:

The pvalue of the test is 0.7188 > 0.05, which means that there is not enough statistical evidence based on the sample to dispute the results of the study published in Psychiatry Research.

Step-by-step explanation:

Test if there is enough statistical evidence based on the sample to dispute the results of the study published in Psychiatry Research:

This means that at the null hypothesis we test if the proportion is 62%, that is:

[tex]H_0: p = 0.62[/tex]

At the alternate hypothesis, we test if the proportion is different from 0.62, that is:

[tex]H_a: p \neq 0.62[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample

62% is tested at the null hypothesis:

This means that [tex]\mu = 0.62, \sigma = \sqrt{0.62*0.38}[/tex]

When a random sample of 26 autistic children were observed, 17 were found to be left-handed.

This means that [tex]n = 26, X = \frac{17}{26} = 0.6538[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.6538 - 0.62}{\frac{\sqrt{0.62*0.38}}{\sqrt{26}}}[/tex]

[tex]z = 0.36[/tex]

Pvalue of test and decision:

The pvalue of the test is the probability of a proportion that differs from the mean by at least 0.6538 - 0.62 = 0.0338, which is P(|z| > 0.36), which is two multiplied by the pvalue of z = -0.36

Looking at the z-table, z = -0.36 has a pvalue of 0.3594

2*0.3594 = 0.7188

The pvalue of the test is 0.7188 > 0.05, which means that there is not enough statistical evidence based on the sample to dispute the results of the study published in Psychiatry Research.


One number is 5 more than 4 times another. Their sum is 40. Find the two numbers.

Answers

Answer:

7 and 33

Step-by-step explanation:

Two equations:

x = 5 + 4y

x + y = 40

Substitute x for 5 + 4y:

5 + 5y = 40

5y = 35

y = 7

Substitute y for 7:

x = 5 + 4(7)

x = 33

(3-9i)(3+9i) =
(Simplify your answer. Type your answer in the form a +bi.)

Answers

Answer:

[tex]90[/tex]

Step-by-step explanation:

Expand (3-9i)(3+9i) using the FOIL Method.

[tex]3 \times 3 + 3(9i) - 9i \times 3 - 9i(9i)[/tex]

Simplify and combine like terms.

[tex]90[/tex]

therefor, the answer is 90.

I think it’s 90
I hope it’s correct

what is the formula of finding square rood

Answers

Answer:

[tex] \huge\blue{ \mid{ \underline{ \overline{ \tt ♡ ANSWER ♡ }} \mid}}[/tex]

There's no specific formula to find the square root of a number, however we can find the square root of a number by the following methods:

i) By Prime Factorisation

ii) By Long Division

iii) By Repeated subtraction method

✏ By Prime Factorisation:

Step I: Obtain the given number.

Step II: Reduce the given number into prime factors by successive division.

Step III: Now make pairs of prime factors in such a way that both the factors in each pair are equal.

Step IV: Take one factor from each pair and find the product of these factors.

Step V: The product obtained by multiplying the factors is the required square root.

✏ Long Division:

Step 1: Firstly, we place a bar on every pair of digits starting from the unit digit. If the number of digits in it is odd, we put a bar on the single-digit too.

Step 2: Now we find the largest number whose square is less than or equal to the 1st number.

Step 3: Now we bring down the next bar number.

Step 4: For new divisor, we add the divisor & quotient.

Step 5: Number taken is the product of a new divisor and this digit is equal to or less than the new dividend.

✏ Repeated subtraction method:

In this method, the given number is subtracted by 1, 3, 5, 7,… at every step till you get zero at the end. The number of steps in the solution is the required square root.

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

Emily is having a bad cold. She uses up of a box of tissues every day. How many boxes of tissues does she need to buy if she expects the cold to last for? days? How many boxes does she need to buy so she doesn't run out of tissues?​

Answers

Answer:

Step-by-step explanation:

1 per day  Taylor , but the question doesn't say how many days...  :/

Someone pls help me I’m stuck

Answers

Answer:

center= (0, -9)

r=1

Step-by-step explanation:

formula for circle= (x-h)^2+(y-k)^2= r^2

(h, k)= center

r= radius

We know that h is 0 since (x-h)^2 is x^2.

We know k= -9 from (y+9)^2

since r^2=1

r=1

12. Which of these is not a characteristic (property) of a polygon?
A. A closed shape
B. Parallel faces
C. Made of straight lines
D. Two-dimensional

Answers

B. Parallel faces

Not all sides need to be parallel and a polygon has only 1 face unless cut

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