Statistics

A researcher is interested in the number of days that successful athletes train to run a full marathon. She gets the workout logs for one year for all the athletes who completed a specific marathon in less than four hours. On the average, these athletes of the past trained for 305 days per year. She is in charge of the training for 20 athletes. After they run the marathon, she wonders whether their training differed in amount from the training of successful athletes in the past. She records the number of days of training for her 20 athletes. She uses SPSS to determine if her athletes trained a different number of days than the successful athletes.
The SPSS results are shown below.
Test Value = 305
95% Confidence Interval of the Mean Difference (11 Sig. (2-tailed) Difference Lower Upper
Days -4 876 19 000 -42.800 -61 17 -24,43
Answer the following: 1. Write out the null and alternative hypotheses.

2. What type of test is the appropriate test and explain why it is the appropriate test.

3. Using a level of significance for 0.05, what is your decision about the null hypothesis and what is the conclusion?