Agricultural Statistics And Economics Quiz 5 (20 MCQs)

Quiz Instructions

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1. A famous medical experiment was conducted by the Nobel Laureate Linus Pauling who believed that vitamin C prevents colds. His subjects were 279 French skiers who were randomly assigned to receive vitamin C or a placebo. Of the 139 given vitamin C, 17 got a cold. Of the 140 given the placebo, 31 got a cold. Find and interpret a 95% confidence interval for the difference of two proportions.
2. Which type of sample does a researcher deliberately set the proportions of levels of members chosen within a sample?
3. Which of the following are true statements? I. Correlation requires that there are clearly-identified explanatory and response variables.II. Scatterplots require that both variables be quantitative.III. Every least-squares regression line passes through $ \left(\overline{x}, \ \overline{y}\right)$
4. The 99% confidence interval for a proportion is (0.54, 0.72). What is the point estimate?
5. Census is
6. When we test np and n(1-p) to ensure they are both greater than or equal to 10, what are we trying to determine?
7. When p-value is greater than alpha we:
8. If 5 is added to every value in a data set, how does this affect the measure of center?
9. Which of the following statement is incorrect?
10. What type of sampling? Twenty-five students are randomly selected from each grade level at a high school and surveyed about their study habits.
11. The correlation between the heights of fathers and the heights of their (fully grown) sons isr = 0.52. This value was based on both variables being measured in inches. If fathers'heights were measured in feet (one foot equals 12 inches), and sons' heights were measuredin furlongs (one furlong equals 7920 inches), the correlation between heights of fathers andheights of sons would be
12. What is the critical value z* for a 99% confidence interval?
13. A 90% confidence interval for the mean speed driven by cars on East Main St. is given by (21, 45). What was the sample mean of this study?
14. A TV show host asks his viewers to visit his website and respond to an online poll.What type of sample is this?
15. Which of the following sources of error is included in the margin of error
16. Which of the following is an open ended question?
17. At a local community College, five math classes are randomly selected out of 20 and all of the students from each class are interviewed.
18. If the p-value > $ \alpha$, then the sample is not unusual if the null is true, so we ..... the null, so there is not convincing evidence that the alternative hypothesis is true, so the results are .....
19. What does the square of the correlation (r2) measure?
20. It is a variable that can assume any numerical value over an interval or intervals.