170 students were asked to randomly pick one of the numbers 1, 2, 3, 4, 5, 6, 7,
ID: 3062392 • Letter: 1
Question
170 students were asked to randomly pick one of the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The number 7 was picked by 51 students.
(a) For the sample, calculate the proportion of students who picked 7. (Round the answer to three decimal places.)
(b) Calculate the standard error for this sample proportion. (Round the answer to three decimal places.)
(c) Calculate a 90% confidence interval for the population proportion. (Round the answer to three decimal places.)
(d) Calculate a 95% confidence interval for the population proportion. (Round the answer to three decimal places.)
(e) Calculate a 98% confidence interval for the population proportion. (Round the answer to three decimal places.)
(f) What do the results of parts (c)-(e) indicate about the effect of confidence level on the width of a confidence interval? (Select all that apply.)
As the confidence level is decreased, the width of the interval decreases.
As the confidence level is decreased, the width of the interval increases.
As the confidence level is increased, the width of the interval increases.
As the confidence level is increased, the width of the interval decreases.
(g) On the basis of these confidence intervals, do you think that students choose numbers "randomly"? Yes/No?
Explanation / Answer
a)
b)
c)
d)
e)
( please try 0.218 ; 0.382 if above does not work due to rounding error)
f)
As the confidence level is decreased, the width of the interval decreases.
As the confidence level is increased, the width of the interval increases.
g)
No (as all interval are above 0.1 frm true mean proportion of 0.1)
x = 51 sample size n = 170 sample proportion p x/n= 0.3000Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.