Question

an internet provider contacts a random sample of 300 customers and asks how many hours per week the customers use the internet. the responses are summarized in the provided dotplot. the average amount of time spent on the internet per week was 7.2 hours, with a standard deviation of 7.9 hours. 6 12 jes 30 18 24 hours of internet use per week 36 42 if we want a margin of error of 0.5 hours, how large of a sample would we need? 944 people 952 people 953 people 960 people

Answer 1

To achieve a margin of error of 0.5 hours, a sample size of 952 approximately 956.17 people would be needed. The correct answer is 960 people.

Step-by-step explanation:

To determine the sample size needed to achieve a margin of error of 0.5 hours, we can use the formula:

n = (Z^2 * σ^2) / E^2

Where:

• n is the sample size
• Z is the Z-score corresponding to the desired confidence level (e.g., for a 95% confidence level, Z = 1.96)
• σ is the standard deviation
• E is the margin of error

Plugging in the values from the given information:

n = (1.96^2 * 7.9^2) / 0.5^2

n ≈ 959.17

Therefore, we would need a sample size of approximately 959.17 approximately 960 people.