# MS 150 Statistics q09 • Name:

Jan height/cm June height/cm
8540
7050
6015
6050
7030
5030
6040
4030
5050
3040
4060
5050
1530
3020
4030
5050

On 04 January 2008 the wave heights in centimeters were recorded for translating waves on the reef in Piyuul. Waves heights were again recorded in June at that location.

1. __________ What is the sample mean x for the waves in January?
2. __________ What is the sample mean x for the waves in June?
3. Using five classes, fill in the following frequency table for the January data.
Jan class upper limitsFrequency FRelative Frequency
Sums:
1. Using five classes, fill in the following frequency table for the June data.
Jun class upper limitsFrequency FRelative Frequency
Sums:
1. Sketch two relative frequency histograms, one for the January data and one for the June data.
2. ____________ Run a t-test for a difference of the mean wave heights for January and June. Use an independent samples t-test. What is the p-value?
3. ____________ What is the maximum confidence c that we can have that the difference between January and June wave heights is significant?
4. ____________ At an alpha α of 5%, would we reject a null hypothesis of no difference in the mean wave heights between January and June or would we fail to reject the null hypothesis?