A company offering online speed reading courses claims that students who take their courses show a 5 times (500%) increase in the number of words they can read in a minute without losing comprehension. A random sample of 100 students yielded an average increase of 415% with a standard deviation of 220%. Is there evidence that the company's claim is false?
(a) Are conditions for inference satisfied?
(b) Perform a hypothesis test evaluating if the company's claim is reasonable or if the true average improvement is less than 500%. Make sure to interpret your response in context of the hypothesis test and the data. Use α= 0:025.
(c) Calculate a 95% confidence interval for the average increase in the number of words students can read in a minute without losing comprehension.
(d) Do your results from the hypothesis test and the confidence interval agree? Explain.