Question

The average undergraduate cost of tuition, fees and books for a two year college is $10,560. Four years later, a random sample 36 two year colleges, had an average cost of tuition, fees and books of $11,380 and a standard deviation of $1300, with a normal distribution. At α = 2%, has the average cost of two-year college increased?

1) Check and state the conditions for statistical inference.

2) Compute a 95% confidence interval for the average cost of tuition fees and books for a two year college.

3) Write a statement interpreting the confidence interval.

4) Write the null and alternate hypotheses.

5) Calculate the standard error and sketch the model, marking the center and ± SD’s

6) Calculate the p-value, showing ALL the work.

7) State the conclusion, remember there are three parts. Remember that α =2% or α =.02.

Answer 1

1) Conditions -

Sample should be from normal population.

Selection of sample should be random.

2) Test Statistics = 3.785

3) P value = 0.0003

4) Decision - Reject H0 if p value < 0.02

5) Conclusion - Average cost of two years of college increased.

any doubts please ask ! thank you :) #stay-safe :)