To better understand the financial burden students are faced with each term, the statistics department would like to know how much their ST 243Z students are spending on school materials on average. Lets use the Spring 2023 ST 243Z class data to calculate a 95% confidence interval to estimate the average amount ST 243Z students spend on materials each term.

The average from our student survey is $246 and the number of students sampled is 90.

Assume .

State the question of interest.

On average, how much do ST 241z students spend on school materials each term?

1. Identify the parameter of interest. If any notation is used, define your notation in the context of the problem.

1. Check the conditions.
   1. Do the data come from a random sample? What are some potential biases about the way the data was collected?

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

1. Set up and calculate the confidence interval. Show work!

Our estimate, = _____ critical value = _____ Standard error,

1. 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!

ST201 Winter 2020 School Materials Cost =$120 x Z n=