Question

In a sample of 25 iPhones, 12 had over 85 apps downloaded. Construct a 90% confidence interval for the population proportion of all iPhones that obtain over 85 apps. Assume zo.05 -1.645. Multiple Choice 0.48±0.16

0481 0.09.
0.29: 0.15 0.29:016

Answer 1

Step-by-step explanation:

we calculated confidence interval = 0.48±0.16

what is confidence interval?

confidence interval represents the accuracy of a particular estimation.

what is proportion of sample?

proportion of population is the ratio of random sample to the total available sample.

Given, size of samples that means number of total iPhones, n = 25

size of random samples that means iPhone with 85 downloaded apps, p= 12,

critical value for 90% confidence interval z* = 1.65

proportion of samples, p^ = p/n = 12/25 =0.48

finally, confidence interval = p^±z*[√{p^(1-P^)/n}]

0.48±1.65[√{0.48(1-0.48)/25}]

hence, the confidence interval = 0.48±0.16