Back to the Table of Contents

An Introduction to Statistics

Homework for Statistics Lesson 4

  1. (6 points) The population of 33 in the senior class of 2009, 8th grade, Algebra Diagnostic Test scores were stratified into groups of 6 taken from the data set in descending order. Using a die, one from each strata was randomly selected to obtain the following results presented in random order:

    44, 63, 70, 74, 100, 141

    Find the sample size, sum of the data, mean, mode, median, and midrange.

     

     

     

  2. Discuss the sampling technique used in the problem above.

     

     

  3. Compare the average results obtained in the problems above with those provided for the full population (or did you lose your summary sheet(s)?).

     

     

  4. (4 points) The digits of e have been shown to be very random. Treating each of the first twenty decimal (i.e. omit the "2.") digits as a separate data element, calculate the mean, mode, median, and midrange for this sample.

     

     

  5. What would you expect each of these average values to be, if say a million or billion digits of e were used?

     

     

  6. Calculate the average growth rate for a portfolio with the following consecutive annual interest rates: 5%, 10%, -5%, 20%, 15%.

     

     

  7. Four students drive from Michigan to Florida (2000 km) at 100.0 kph and return at 80.0 kph. Find the average round trip speed, using the harmonic mean.

     

     

  8. For the problem just above, what is their average round trip velocity?

     

     

  9. Tom Foolery measures the voltage in a standard outlet as 120 volts, -160 volts, 95 volts, and 10 volts at random intervals. Help him calculate the RMS voltage.

     

     

  10. Calculate the GPA (weighted mean) for the following data: Biology, 5 credits, A- (use 3.667); Chemistry, 4 credits, B+ (use 3.333); College Algebra, 3 credits, A (use 4.000); and Health, 2 credits, C (use 2.000); Debate, 2 credits, B (use 3.000). Express your results to three decimal places.

     

     

  11. Using the inauguration ages from the previous homework, calculate the 10% trimmed mean and 20% trimmed mean.

     

  12. A researcher finds the average teacher's salary for each state from the web. He then sums them together, divides by 50 to obtain their arithmetic mean. Why is this wrong and what should he have done?

     

  13. Examine lesson 13.4 in your Geometry textbook and do problems 2-3.
    1. Find the geometric mean of 2 and 50 to the nearest hundredth.

    2. Find the geometric mean of 9 and 12 to the nearest hundredth.

BACK TO LESSON ODD SOLUTIONS ACTIVITY CONTINUE