Question

A light bulb manufacturer wants to estimate the proportion of light bulbs being produced that are defective. A random sample of 155 light bulbs is selected and 12 are defective. Write the interval (Show all work and circle your final answer), and

a. Find the sample proportion ?̂.

b. Create a 95% confidence interval (round to 3 decimal places) for the population proportion of defective lightbulbs being produced.

c. Write a sentence interpreting this.

d. Using the sample proportion from part (a), suppose we wanted to compute a 95% confidence interval where the population proportion of defective lightbulbs was within 1%. What is the minimum sample size needed for this?

e. Circle your answer below: For part (b), if we increased confidence level to 99%, and kept the same sample size, the width of the interval would become Narrower Wider Stay the same

Answer 1