Do phone surveys provide adequate coverage of households with respect to one particular parameter? The parameter is the proportion of households without children. If telephone surveys provide adequate coverage of households, then p , the proportion of households without children in the set of all future samples reached by phone, must be equal to the proportion of households without children in the population of all households. Suppose that Thomas, a market analyst, contacts a simple random sample of 300 households as part of a national telephone survey. Of the households contacted, 129 households, or 43 %, have no children and 57 % have at least one child. The most recent census indicates that 48 % of all households have no children and 52 % have at least one child.

The 95% confidence interval is (8.3%,17.7%), and the correct option is C.

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In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

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13% of a sample of 200 students do not like ice cream.

This means that [tex]\pi = 0.13, n = 200[/tex]

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95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

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The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.13 - 1.96\sqrt{\frac{0.13*0.87}{200}} = 0.083[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.13 + 1.96\sqrt{\frac{0.13*0.87}{200}} = 0.177[/tex]

------------------------------------------

As a percentage:

Thus, the 95% confidence interval is (8.3%,17.7%), and the correct option is C.

A similar problem is given at https://brainly.com/question/22223066

Answer:

Step-by-step explanation:

60°=2×30°

one angle is double the angle of the same right angled triangle.

so hypotenuse is double the smallest side.

Hypotenuse=10

smallest side=10/2=5

third side =√(10²-5²)=5√(2²-1)=5√3

Answer:

The 95% confidence interval is   [tex]0.88 < \mu_1 - \mu_2 < 5.12[/tex]

Step-by-step explanation:

From the question we are told that

   The  sample mean for fat-blocking [tex]\= x_1 = 13.7[/tex]

     The  sample size  for fat-blocking  [tex]n = 12[/tex]

      The standard deviation for  fat-blocking is [tex]\sigma_1 = 2.6[/tex]

      The  sample mean for control group is  [tex]\= x _2 = 10.7[/tex]

      The  sample size  for control group is [tex]n_2 = 12[/tex]

      The standard deviation for control group is [tex]\sigma _2 = 2.4[/tex]

Given that the confidence level is  95% then the level of significance can me mathematically evaluated as

                 [tex]\alpha = 100 - 95[/tex]

                 [tex]\alpha = 5 \%[/tex]

                    [tex]\alpha =0.05[/tex]

Generally the degree of freedom is mathematically represented as

           [tex]df = n_1 + n_2 - 2[/tex]

substituting values

           [tex]df = 12 +12 - 2[/tex]

           [tex]df = 22[/tex]

Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] at a degree of freedom of  22 form the students t-distribution , the value is  

                [tex]t_{\frac{\alpha }{2}, df } = 2.074[/tex]

Generally the margin of error is mathematically represented as

            [tex]E = t_{\frac{\alpha }{2}, df } * \sqrt{ \frac{\sigma^2_1 }{n_1 } + \frac{\sigma^2_2 }{n_2 } }[/tex]

substituting values

            [tex]E = 2.07 4 * \sqrt{ \frac{ 2.6^2 }{12 } + \frac{2.4^2 }{12 } }[/tex]

           [tex]E = 2.12[/tex]

the 95% confidence interval for the differences of the means is mathematically represented as

        [tex]\= x_1 - \= x_2 - E < \mu_1 - \mu_2 < \= x_1 - \= x_2 + E[/tex]

substituting values

       [tex]13.7 - 10.7 - 2.12 < \mu_1 - \mu_2 < 13.7 - 10.7 + 2.12[/tex]

      [tex]0.88 < \mu_1 - \mu_2 < 5.12[/tex]

9514 1404 393

Answer:

  perimeter ≈ 12.4 units

Step-by-step explanation:

The side adjacent to the angle is given. The relationships useful for the other two sides are ...

  Tan = Opposite/Adjacent

  Cos = Adjacent/Hypotenuse

From these, we have ...

  opposite = 5·tan(22°) ≈ 2.02

  hypotenuse = 5/cos(22°) ≈ 5.39

Then the perimeter is ...

  P = a + b + c = 2.02 + 5 + 5.39 = 12.41

The perimeter of ∆ABC is about 12.4 units.

Complete Question

Find the probability of winning a lottery with the following rule. Select the  six  winning numbers from​ 1, 2, . . .​ ,34 . ​(In any order. No​ repeats.)

Answer:

The  probability is  [tex]P(winning ) = 7.435 *10^{-7}[/tex]

Step-by-step explanation:

From the question we are told that

     The  total winning numbers   n =  34

      The total number to select is   r =  6

The total outcome of  lottery is mathematically represented as

      [tex]t_{outcome}) = \left n } \atop {}} \right. C_r[/tex]

      [tex]t_{outcome}) = \frac{n! }{(n-r )! r!}[/tex]

substituting values

      [tex]t_{outcome}) = \frac{ 34 ! }{(34 - 6 )! 6!}[/tex]

      [tex]t_{outcome}) = \frac{ 34 ! }{28 ! 6!}[/tex]

     [tex]t_{outcome}) =1344904[/tex]

The  number of desired outcome is  

           [tex]t_{desired} = 1[/tex]

 this is because the desired outcome is choosing the six winning number

   The probability of winning a lottery is mathematically represented as

      [tex]P(winning ) = \frac{t_{desired}}{t_{outcome}}[/tex]

substituting values  

     [tex]P(winning ) = \frac{1}{1344904 }[/tex]

      [tex]P(winning ) = 7.435 *10^{-7}[/tex]

Answer:

(g÷f) (x) (1.8) ³x²+⁷x+2

Step-by-step explanation:

Im glad to help you

Step-by-step explanation:

Option A and B are the correct answer because it equal to 688.5 and 688.05

Answer:

it is 1377/2 and 688 1/17 thats the answer

Step-by-step explanation:

Answer:

540 and 50 respectively

Step-by-step explanation:

Let the speed of plane in still air be x and the speed of wind be y.

ATQ, (x+y)*7.5=4425 and (x-y)*7.5=3675. Solving it, we get x=540 and y=50

Answer:

800= about 1.76 lbs

700= about 1.54 lbs

(there are about 453.5 grams in a pound

Step-by-step explanation:

Answer:

800 grams = 1.76  pounds

700 grams =  1.54  pounds

Step-by-step explanation:

i googled it

Answer:

33.33 percent

Step-by-step explanation:

Answer:

13

Step-by-step explanation:

Make a proportion

part/whole = part/whole

1.3/x=10/100

130=10x

x=13

Answer:

67

Step-by-step explanation:

DM=JM-JD=84-17=67

Answer:

Step-by-step explanation:

Answer:

1500.

There is no need to round here, it is already exact.

Complete Question

The complete question is shown on the first uploaded image

Answer:

The 95% confidence interval is  [tex]49.85 < \mu < 54.15[/tex]

This means that there is 95% chance that the true population mean is within this interval

Step-by-step explanation:

From the question we are told that

    The  sample size is n = 30  

    The sample mean is  [tex]\= x = 52[/tex]

    The population standard deviation is  [tex]\sigma = 6[/tex]

Given that the confidence level is 95% then the level of confidence is evaluate as

             [tex]\alpha = 100 - 95[/tex]

            [tex]\alpha = 5\%[/tex]

            [tex]\alpha = 0.05[/tex]

Next we obtain the critical value of  [tex]\frac{\alpha }{2}[/tex] from the normal distribution table , the values is

                 [tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]

Generally the margin of error is mathematically represented as

           [tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]

substituting values

            [tex]E = 1.96 * \frac{ 6 }{\sqrt{30} }[/tex]

           [tex]E = 2.147[/tex]

The  95% confidence interval is mathematically represented as

          [tex]\= x - E < \mu < \= x + E[/tex]

substituting values

         [tex]52 - 2.147 < \mu < 52 + 2.147[/tex]

         [tex]49.85 < \mu < 54.15[/tex]

Answer:

The product decreases 2022.

Step-by-step explanation:

(x + 1)(y - 1) = xy + 2020

xy - x + y - 1 = xy + 2020

-x + y = 2021

(x - 1)(y + 1) = xy + x - y - 1

  + 2021   =       -x + y

----------------------------------

(x - 1)(y + 1) + 2021 = xy - 1

(x - 1)(y + 1) = xy - 2022

The product decreases 2022.

Answer:

A. 385.56 square meters.

B. 142.56 square meters.

Step-by-step explanation:

A house 27m by 9m is surrounded by a walkway 1.8m wide.

a) Find the area of the region covered by the house and the walkway.

​b) Find the area of the walkway.

Let

Length of the house=l=27m

Width of the house=w=9m

Wideness of the walkway=x=1.8m

Area of the region covered by the house and the walkway

=( L + 2*x) * (w + 2*x)

= (27+2*1.8)*(9+2*1.8)

=(27+3.6)*(9+3.6)

=(30.6)*(12.6)

=385.56 square meters.

​b) Area of the walkway

= (L + 2*x)*(w + 2*x) - l*w

= (27+2*1.8)*(9+2*1.8) - 27*9

=(27+3.6)*(9+3.6) - 243

=(30.6)*(12.6) - 243

=385.56 - 243

=142.56 square meters.

Answer:

4b³ + 11b² - 6b + 13

Step-by-step explanation:

Subtract like terms.

6b³ - 2b³ = 4b³

3b² - (-8b²) = 3b² + 8b² = 11b²

0 - 6b = -6b

8 - (-5) = 13

All together, the difference is 4b³ + 11b² - 6b + 13.

Answer:

Farah: x

Ibtisam: x-3

Muna: 2(x-3) or 2x-6

Sum of all their ages: 4x-6

Step-by-step explanation:

Farah is x, so we don't need an expression for that.

Ibtisam is 3 years younger than Farah, which means that we need to subtract 3 from Farah, and that would be Ibtisam's age. x-3.

Muna is 2 TIMES Ibtisam's age, so we need to multiply whatever expression taht was used for Ibtisam by 2. Put brackets around the equation with 2 outside: 2(x-3). Solve and you get 4x-6

Now, you have all their ages in expression form, now you need to simplify by adding:

x+x+2x-6

We cannot simplify -6, so we put that aside. Add all the x's and you get 4x, insert the minus 6 at the end:

4x-6

Hope this helps!

--Applepi101

Answer:

a) X -3

b) 4x - 9

Step-by-step explanation:

a) Farah's age is X so Ibtisam will be X - 3 old since he is 3years younger than Farah

b) Farah is X years old

Ibtisam is X - 3 years old

Muna is 2(X -3) since she is 2 times older than Ibtisam.

the sum of Thier ages will be

X + X -3 + 2(x-3)

= 2x - 3 + 2x - 6

= 4x - 9

Answer:

Probabilty of both Black

= 1/6

Step-by-step explanation:

A bag contains five white balls and four black balls.

Total number of balls= 5+4

Total number of balls= 9

Probabilty of selecting a black ball first

= 4/9

Black ball remaining= 3

Total ball remaining= 8

Probabilty of selecting another black ball without replacement

= 3/8

Probabilty of both Black

=3/8 *4/9

Probabilty of both Black

= 12/72

Probabilty of both Black

= 1/6

Answer:

9/20

Step-by-step explanation:

450/1000

this is not the answer, because it is not simplified

so here we have to find common factor and simplifying

________________________________________________

450/1000 is simplified to 9/20, and it can no longer be simplified.

Answer:

0.235 = 0.24

13.467 = 13.47

0.24+13.47=13.71

Answer:

Yes it suggest that the actual percentage of type A donations differs from 40%, the percentage of the population having type A blood.

Well if a significance level of 0.05 is used it will not affect the conclusion

Step-by-step explanation:

From the question we are told that

     The  sample size is   [tex]n = 149[/tex]

     The  number that where  type A blood is  k =  76

       The population proportion is   [tex]p = 0.40[/tex]

       The  significance level is  [tex]\alpha = 0.01[/tex]

Generally the sample proportion is mathematically represented as

      [tex]\r p = \frac{k}{n}[/tex]

=>    [tex]\r p = \frac{76}{149}[/tex]

=>    [tex]\r p = 0.51[/tex]

The  Null hypothesis is   [tex]H_o : p = 0.41[/tex]

The  Alternative hypothesis is  [tex]H_a : p \ne 0.40[/tex]

Next we obtain the critical value of [tex]\alpha[/tex] from the z-table.The value is  

       [tex]Z_{\alpha } = Z_{0.01} = 1.28[/tex]

Generally the test statistics is mathematically evaluated as

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

substituting values

           [tex]t = \frac{0.51 - 0.40 }{ \sqrt{ \frac{0.40 (1-0.40 )}{149} } }[/tex]    

           [tex]t =2.74[/tex]

So looking at the values for t  and  [tex]Z_{0.01}[/tex] we see that  [tex]t > Z_{0.01}[/tex] so we reject the null hypothesis. Which means that there is no sufficient evidence to support the claim

Now if [tex]\alpha = 0.05[/tex] , the from the z-table the critical value for [tex]\alpha = 0.05[/tex] is  [tex]Z_{0.05} = 1.645[/tex]

So comparing the value of  t and  [tex]Z_{0.05} = 1.645[/tex]  we see that [tex]t > Z_{0.05}[/tex] hence the conclusion would not be different.

Answer:

2016

Step-by-step explanation:

using USA dollars:

$42000 x .072 (7.2%) = 3024 total commission

3024 x 2/3 = 2016 brokers amount

Answer:

Question 1: the angle of y is the same as 49 degrees.

So, y = 49 degrees.

y + x = straight line

=> Straight line = 180 degrees

=> 49 + x = 180

=> 49 - 49 + x = 180 - 49

=> x = 131

Answer to Question 1:

x = 131 degrees

y = 49 degrees

Question 2: Angle x is  the same as 119 degrees

x + y = straight line

=> Straight line = 180 degrees

=> 119 + y = 180

=> 119 - 119 + y = 180 - 119

=> y = 61

y + z = straight line

=> Straight line = 180 degrees

=> 61 + z = 180

=> 61 - 61 + z = 180 - 61

=> z = 119

Answer to Question 2:

x = 119 degrees

y = 61 degrees

z = 119 degrees

Answer:

The horsepower of the carriage is 50

Step-by-step explanation:

Let the horsepower of the carriage=x

ATQ, 195+5=4x, x=50.

Answer:

[tex]10a + 5(a - 3) = 15 \\ 10a + 5a - 15 = 15 \\ 15a = 30 \\ a = \frac{30}{15} \\ a = 2 \\ 10 \times 2 + 5(2 - 3) = 15 \\ 20 + - 5 = 15 \\ 15 = 15 \\ lhs = rhs\\ thank \: you[/tex]

Answer: a = 2

Solve:

Given

10a + 5 (a - 3) = 15

Expand parentheses and apply the distributive property

10a + 5 · a - 5 · 3 = 15

10a + 5a - 15 = 15

Combine like terms

(10a + 5a) - 15 = 15

15a - 15 = 15

Add 15 on both sides

15a - 15 + 15 = 15 + 15

15a = 30

Divide 15 on both sides

15a / 15 = 30 / 15

[tex]\boxed{a=2}[/tex]

Check:

Left-hand side = 10a + 5 (a - 3)

Left-hand side = 10(2) + 5 (2 - 3)

Left-hand side = 20 + 5(-1)

Left-hand side = 20 - 5

Left-hand side = 15

Right-hand side = 15

15 = 15, therefore, [tex]\boxed{a=2}[/tex] would make the equation true.

Hope this helps!! :)

Please let me know if you have any questions

Answer:

-

Step-by-step explanation:

Forget using calculators.

Test each point by plugging its coordinates into the equation, and checking if the equation holds true.

Don't bother testing (-3,0), because you can't take the square root of -3.

Answer: Please Give Me Brainliest, Thank You!

2

Step-by-step explanation:

There are two variables here, X and Y

Answer:

x > 22

Step-by-step explanation:

Hey there!

Well to solve,

52 - 3x < -14

we need to single out  x

52 - 3x < -14

-52 to both sides

-3x < -66

Divide both sides by -3

x > 22

The < changes to > because the variable number is a - being divided.

Hope this helps :)

Answer:

x > 22

Step-by-step explanation:

First, rearrange the equation

Then, pull out the like terms:

Next, apply algebra to the equation by dividing each side by -3. It should now look like this: x > 22.

Therefore, the solution set of the inequality would be x > 22.