Question

Question 6

An Internet service provider sampled 474 customers, and finds that 102 of them experienced an interruption in high-speed service during the previous month. What is the upper bound for the 99% confidence interval for the proportion of customers who experienced an interruption?

Round to three decimal places (for example: 0.419). Write only a number as your answer.

Question 7

In the computer game World of Warcraft, some of the strikes are critical strikes, which do more damage. Assume that the probability of a critical strike is the same for every attack, and that attacks are independent. During a particular fight, a character has 265 critical strikes out of 550 attacks. What is the lower bound for the 99% confidence interval for the proportion of strikes that are critical strikes.

Round to three decimal places (for example: 0.419). Write only a number as your answer.

Question 8

In a sample of 45 water specimens taken from a construction site, 20 contained detectable levels of lead. What is the upper bound for the 90% confidence interval for the proportion of water specimens that contain detectable levels of lead.

Round to three decimal places (for example: 0.419). Write only a number as your answer.

Answer 1

Q6) The sample proportion is   

For 99% confidence interval the critical value is

Hence the upper bound is

Q7)  The sample proportion is   

For 99% confidence interval the critical value is

Hence the upper bound is

Q8)  The sample proportion is   

For 90% confidence interval the critical value is

Hence the upper bound is