Probability and Chi-square analysis lab
For all problems show your work!
Exercise 1:
A professor and her husband are planning to have a total of 4 children.
(a) What is the probability that all 4 children will be girls?
(b) What is the probability that they will have a girl first, followed by 3 boys?
(c) What is the probability that they will have a girl, a girl, a boy and another girl? (in this
order)
(d) Do you see a pattern with the probabilities in a-c? Describe or summarize in your own
words the results for a-c.
(e) What is the probability that they will have three girls and a boy, regardless of the
order? How (if at all) does this differ from your answers in a-c?
Exercise 2:
Each group will be given a single die. Working as a group, roll the die and begin to
tabulate the frequency in which you roll each number.
1. What is the probability of rolling any one of the 6 numbers?
2. What is the frequency of each number after 10 rolls? After 50 rolls?
Number
Frequency (10 rolls)
Frequency (50 rolls)
1
2
3
4
5
6
3. Compare the expected frequency vs. the observed for 10 rolls and 50 rolls using Chisquared analysis.
What is your null hypothesis for each? (10 and 50 rolls)
Do you reject or accept your null hypothesis in each case.
Be sure to show your work.