Stats Homework

CE 103

Statistics Homework Problems

Homework #3: Problems 1-2 are due in class on February 27, 2007.

1. For the data on page 45, problem 2.8 in SS, do the following.

a. Using Excel construct histograms with two different choices for class intervals (one could be the default).

b. Compute the mean, median, standard deviation, 25th percentile using Excel functions.

c. Based on the shape of the histogram, do you think that the data are normally distributed and why?

d. Estimate the probability that a random student from this population will weigh more than 150 pounds.

2. Now suppose that these same data from problem 2.8 are annual maximum 24-hour rainfall depths in mm for a particular location. Do the following.

a. Rank the observations and determine the exceedence probability associated with each event.

b. Determine the exceedence probabilities and percentiles associated with the 2-year and 10-year return period storms.

c. Using the ranked data, estimate the magnitudes of these two events in mm for the location corresponding to this data set.

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Homework #4: Problems 3-8 are due in class on March 6, 2007.

3. a. Work problem 7.7 in SS both by hand and using Excel.

b. Solve the problem again using Excel for p=0.02 and n=50.

4. Work problem 7.14 in SS.

5. Work problem 7.15 in SS.

6. Work problem 7.17 in SS, parts a, b, c, d only. Use the normal table in SS for parts and b, and use the Excel function NORMDIST for parts c and d.

7. Work problem 7.18 in SS, parts a and b only. Use the normal table for part a and the Excel function NORMINV for part b.

8. Work problem 7.23 in SS. Use Excel.

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