INFO 240: Business Statistics
Sample Practice Problems for Midterm
1A. Write down two examples of categorical, numerical discrete and numerical continuous data related to some sport of your choice.
1B. Explain random variable with an example.
2.. One investor has $200K in stocks, $150K in bonds, $100K in CDs and $50K in cash. Show this portfolio in the form of a bar chart and a pie-chart and explain the charts,
3. At a party, there are 11 people with these ages (years):
10,15,20,25,30,35,40, 45, 50, 55, 60
Calculate the mean, median, variance and standard deviation of the data. Explain what they mean.
4.. Plot a stem and leaf diagram, and a histogram for the following data and explain the charts,
40, 41, 43, 49, 50, 51, 53, 54, 56, 57, 59, 60, 60, 60, 65, 65, 66, 67, 70, 70, 70, 74, 75,75, 75, 76, 78, 79, 79, 79, 80, 80, 81, 81, 82, 82, 83, 85, 86, 87, 88, 89, 90, 91, 91, 92, 93, 93, 94, 95.
5. For the data in Problem 4:
a. Plot a Stem and Leaf Diagram
b. Plot a box chart for the data in Problem 4.
6.. Given the contingency table as below:
| Male | Female | ||
| Voted in an election | 25 | ||
| Did not Vote | 60 | ||
| 45 | 55 |
A. Fill the missing data
B. Calculate the probability of selecting a male or someone who voted.
C. Calculate the probability of selecting someone who is a female and who voted.
D. Calculate the probability that a non-voter is a female?
E. Is the voting behavior independent of gender?
F. Which events are mutually exclusive?
7.The probability of producing a defective product in a process is 0.1. A sample of 15 products was selected.
A. What is the probability of 2 products being defective?
B. What is the probability that the number of defective products are between 1 and 3?
C. What is the probability that not more than 2 products will be defective?
D. What is the probability that less than 2 products are defective?
8, Calls are arriving randomly at a 911 call Office in a city at the average rate of 10 calls per minute.
a. What is the probability of 10 calls in the next one minute?
b. What is the probability that the calls in the next one minute are less than 5?
c. What is the probability that the calls are more than 10?
