Question

In a survey conducted by a reputable marketing agency, 231 of 1000 adults 19 years of age or older confessed to bringing and using the cell phone every trip to the bathroom (contessons included testing and answering phone calls Complete parts (a) tough below Click here to view the standard normal distribution table 1). Click here to view the standard romal distrution lean 21 Why is the pointestinale found in part (c) a random variable? DA being used to make Werences 3. Itse is based on a sample C. The le size is large o its value may change depending on the individuals in the survey E is information obtained from a survey What is the source of variability in the random variatie? DA Testin asked in the survey The individuals sected to be in the way The same su Ranum errors Le Construct and were confidence varvalor potion proportion of the 18 years of age or older who bring the cell phone every toe balloon Select the correct choice bow and in any war boxes with your (Troegers decimals rounded to decimal places and Use ascending on A There is probably the proportion of aduts to yours of age order who bring or colphone every to the bathroom is between and OS Wewe confident the proportion of auta 18 yows of age or older to bring or colphone every to the broom is between

Answer 1

S0lution:

Given;

n= 1000 sample size of adults

X = 231 adults 19 years age or older bring cell phone every trip to the bathroom

$\alpha=0.05$ Level of significancce

The point estimate for population proportion p is

Sample proportion of adults 19 years age or older who bring there cell phone every trip to the bathroom.

231 р = 0.231 n 1000

$\hat q=1-\hat p=0.769$

The point estimate is the random variable because its value change depending on the individual in the survey.

option D is correct

The source of variability in the random variable is the individual selected in the study.

Option B is correct

The 95% confidence interval for population proportion of adults 19 years age or older who bring there cell phone every trip to the bathroom is

p*(1-P) p Za/2* V n

At $\alpha=0.05$

$Z_{\alpha/2}=Z_{0.025}=1.96$ From Z table

$(0.231\pm 1.96*\sqrt\frac{0.231*0.769}{1000})$

$(0.231\pm 1.96*\sqrt\frac{0.177639}{1000})$

$(0.231\pm 1.96*\sqrt 0.0001776)$

$(0.231\pm 1.96*0.0133266)$

$(0.231\pm 0.0261202)$

(0.231 -0.0261202, 0.231 +0.0261202)

(0.204879, 0.2571202)

(0.205, 0.257)

Interpretation of Confidence interval

we are 95% confident that the proportion of adults 19 years age or older who bring there cell phone every trip to the bathroom is between 0.205 and  0.257

option B is Correct