Statistics Homework

Name: ______________________________________

Problems: 10 points each.

1. We have the following set of data for weights of our basketball players: 145, 213, 174, 198, 240, 201, 188, 215, 196, 201.
   What is the mean weight? What is the median weight? What is the mode?
   
   
   
   
   
   
   
2. Draw a histogram for the following data for student GPAs:
   1.2, 1.8, 2.1, 2.2, 2.4, 2.7, 2.9, 3.1, 3.1, 3.2, 3.2, 3.4, 3.6, 3.8, 3.9, 4.0
   
   
   
   
   
   
   
   
   
3. Calculate the standard deviation for the data series in the previous question.
   
   
   
   
   
   
   
   
   
4. We have the following set of data for ages of students in a class: 23, 43, 19, 19, 62, 18, 19, 27, 29, 17, 38.
   What is the mean age? What is the median age? What is the mode?
   
   
   
   
   
   
   
5. Draw a histogram for income distribution at a company if we have employees making: $30,000; $32,000; $36,000; $44,000; $48,000; $52,000; $53,000; $57,000; $59,000; $61,000; $63,000; $72,000; $78,000; and $84,000.
   
   
   
   
   
   
   
   
   

Multiple Choice: 5 points each.

1. Imagine a multiple choice test with four questions, each with four answers.
   What are the odds that two students guessing randomly will turn in the exact same test?
   (By same test, I mean each answer is identical.)
   1. 1 in 4
   2. 1 in 44
   3. 1 in 256
   4. 1 in 400
2. Coney Island usually see a shark attack once every ten years.
   We read about a shark attack on August 15. On August 16, the probability of a shark attack is still:
   1. one per every ten years.
   2. 1 in 2
   3. can't say: the events are not independent.
   4. very low: that could never happen two days in a row.
3. If a distribution has a "fat tail," that means:
   1. We will need a much larger sample than with a Bell Curve to really know what is going on.
   2. There is a fat chance of finding out anything about it.
   3. The mean, median and mode will all be the same.
   4. We can model it just like a normal distribution.
4. Our confidence in a population sample depends upon
   1. the honesty of people's answers.
   2. the sample size.
   3. having a truly random sample.
   4. all of the above.
5. Statistics that tell us about the central tendency of a distribution include:
   1. the mean, the mode, and the median.
   2. probability, set theory, and expectations.
   3. skewness, kertosis, and gamma.
   4. the variance, the standard deviation, and the range.
6. We use random sampling because
   1. it is less work that way.
   2. statisticians love their random number generators.
   3. it is too expensive to do anything else.
   4. it doesn't assume we already know about the population.
7. If we have a population with a normal distribution, the best measure of its average is:
   1. the mean.
   2. the median.
   3. the mode.
   4. won't matter, they will be the same.
8. Statistics that tell us about the spread of a distribution include:
   1. the mean, the mode, and the median.
   2. probability, set theory, and expectations.
   3. skewness, kertosis, and gamma.
   4. the variance, the standard deviation, and the range.
9. If we have a population with some very extreme values, the best measure of its average is:
   1. the mean.
   2. the median.
   3. the mode.
   4. the variance.
10. The fact that larger samples usually give us a better window into the whole population than do smaller samples is an example of:
    1. the law of binomial distribution.
    2. the law of large letters.
    3. the law of the jungle.
    4. the law of large numbers.