# MATH 221 Week 8 Final Exam1

**This pack of MATH 221 Week 8 Final Exam1 contains answers on:**

1. Find the equation of the regression line for the given data. then construct A SCATTER PLOT of the data and draw the regression line. (each pair of variables has a significant correlation.) then use the regression equation to predict the value of y for each of the given x- values, if meaningful. the caloric content and the sodium content(in milligrams) for 6 beef ho dogs are shown in the table below.

2. A humane society claims that less that 31% of US households own a dog. In a random sample of 395 us households, 153 say they own a dog. At a=0.01, is there evidence to support the society’s claim?

3. The altitude (in thousands of feet) and speed of a plane (in feet per second) for various altitudes is shown below. Complete parts (a) though (c).

4. A researcher wishes to estimate, with 99% confidence, the proportion of adults who have high speed internet access. Her estimate must be accurate within 3% of the true proportion.

a) Find the minimum sample size needed, using a prior study that found that 42% of the respondents said they have high speed internet access.

b) No preliminary estimate is avaliable. Find the minimum sample size needed.

5. Determine whether the variable is qualitative or quantitative.

6. About 16% of the population of the large country is nervous around strangers. If two people are randomly selected, what is the probability that both are nervous around strangers? What is the possibility at least one is nervous around strangers?

7. The table below shows the number of male and female students enrolled in nursing at a university for a certain semester. A student is selected at random. Complete parts (a) through (d)

a Find the probability that the student is male or a nursing major

P (being male or a being a nursing major)

(Round to the nearest thousandth as needed)

b Find the probability that the student is female or not a nursing major

P(being female or not being a nursing major)

(Round to the nearest thousandth as needed)

c Find the probability that the student is not female or a nursing major

P (not being female or being a nursing major

(Round to the nearest thousandth as needed)

d Are the events “being male” and “being a nursing major” mutually exclusive? Explain

8. A quality control manager randomly selects 30 bottles of tomato sauce that were filled on October 11 to assess the calibration of the filling machine.

1. What is opulation in the study?

2. What is the sample in the study?

9. The state test scores for 12 randomly selected high school seniors are shown on the right.

Assume the population is normally distributed.

a) Find the sample mean

b) Find the sample standard deviation

c) Construct a 95% confidence interval for the population mean