Economics homework help.
Chapter 2
- 1. Consider the following data on distances traveled by 100 people to visit the local park.
distance | freq |
1-8 | 30 |
9-16 | 20 |
17-24 | 25 |
25-32 | 10 |
33-40 | 15 |
Expand and construct the table adding columns for relative frequency and cumulative relative frequency. Then plot Histogram, Frequency Polygon and Ogive Curve.
- Math test anxiety can be found throughout the general population. A study of 250 seniors at a local high school was conducted. The following table was produced from the data. Complete the missing parts.
Score Range | Frequency | Relative Frequency | Cumulative Relative Frequency |
Very anxious | 0.24 | ||
Anxious | 0.40 | ||
Mildly anxious | |||
Generally relaxed | 35 | ||
Very relaxed | 0.18 | ||
- The following frequency table summarizes the distances in miles of 100 patients from a regional hospital.
Distance Frequency
0-4 20
4-8 25
8-12 30
12-16 20
16-24 5
Calculate the sample variance and standard deviation for this data (since it is a case of grouped data- use group or class midpoints in the formula in place of X values, and first calculate the sample mean).
Chapter 5
4. At a college, 50 percent of the students are female, and 30 percent of the students receive a grade of C. About 40 percent of the students are male and “not C” students. Use this contingency table.
Gender\Grade | C | Not C or | |
Female (F) | 0.50 | ||
Male (M) | 0.40 | ||
0.30 |
If a randomly selected student is a C student, what is the probability the student is female?
5 A and B are independent events. Moreover, P(A) = 0.7 and P(B) = 0.3. Determine P(A B), that is, P(A or B)
- In a recent survey of homes in a major Midwestern city, 30% of the homes have a fax machine and 75% have a personal computer. Suppose 15% of the homes have both a fax machine and a personal computer. What is the probability that a randomly selected home does not have a fax machine or does not have a personal computer?
Chapter 6
7. The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a defective calculator is 15%. If 16 calculators are selected at random, what is the probability that more than 5 of the calculators will be defective?
- An important part of the customer service responsibilities of a cable company relates to the speed with which trouble in service can be repaired. Historically, the data show that the likelihood is 0.40 that troubles in a residential service can be repaired on the same day. For the first 7 troubles reported on a given day, what is the probability that more than 4 troubles will be repaired on the same day?
Chapter 7
9. Given the length an athlete throws a hammer is a normal random variable with mean 60 feet and variance 9, what is the probability he throws it between 55 feet and 65 feet?
- If x is a binomial random variable where n = 100 and p = 0.20, find the probability that x is more than 18 using the normal approximation to the binomial. Check the condition for continuity correction.