MS 150 Statistics t2 • Name:

The data is the annual total rainfall in 2007 measured in centimeters for the sites listed. The data was taken from the Pacific ENSO Update, 1st quarter, 2008, Volume 14 Issue number 1 released on January 22, 2008.

1. __________ What level of measurement is the data?
2. __________ Find the sample size n for the data.
3. __________ Find the minimum.
4. __________ Find the maximum.
5. __________ Find the range.
6. __________ Find the midrange.
7. __________ Find the median.
8. __________ Find the mode.
9. __________ Find the sample mean x.
10. __________ Find the sample standard deviation sx.
11. __________ Find the sample coefficient of variation CV.
12. __________ If this data is to be divided into five bins, what is the width of a single bin?
13. Determine the frequency and calculate the relative frequency using five bins (classes, intervals). Record your results in the table provided.

14. Sketch a frequency histogram of the data, labeling your horizontal axis and vertical axis as appropriate.
15. __________ What is the shape of the histogram?
16. ____________________ Calculate the standard error of the mean SE.
17. ____________________ Find the degrees of freedom.
18. ____________________ Calculate t-critical t_c.
19. ____________________ Find the margin of error for the mean E.
20. Calculate the 95% confidence interval for the population mean μ total rainfall.
    
    p(__________ ≤ μ ≤__________) = 0.95

Confidence interval statistics
Statistic or Parameter	Symbol	Equations	OpenOffice
Degrees of freedom	df	n − 1	=COUNT(data)-1
Find a tcritical value from a confidence level c	tc		=TINV(1-c;df)
Standard error of the sample mean	SE		=STDEV(data)/SQRT(sample size n)
Calculate a margin of error for the mean E for n ≥ 5 using sx.	E		=tc*sx/SQRT(n)
Calculate a confidence interval for a population mean μ from a sample mean x and an error tolerance E		x - E ≤ μ ≤ x + E