Question

To better understand the financial burden students are faced with each term, the statistics department would like to know how much their ST201 students are spending on school materials on average. Let’s use our class data to calculate a 95% confidence interval to estimate the average amount ST201 students spend on materials each term.

The average from our student survey is $248 and the number of students sampled is 90.

Assume ? = $220.
State the question of interest.

On average, how much do ST201 students spend on school materials each term?

1. (1 point) Identify the parameter.

2. Check the conditions.

a. (2 points) Does the data come from a random sample? What are some potential biases about the way the data was collected?

b. (1 point) Is the sample size large enough for distribution of the sample mean to be normal according to the rules for Central Limit Theorem?

c. (3 points) Set up and calculate the confidence interval. Show work! ∗σ

Our estimate, x̅ = _______ z critical value = _______ Standard error, √n = __________

d. (3 points) Return to the question of interest and describe your results in this setting. Be sure to include level of confidence used, your point and interval estimates and context!

Answer 1