# Study Giude for Business Statistics Essay

5041 WordsJan 28, 201321 Pages

1. As the degrees of freedom increase, the t distribution approaches the b. normal distribution 2. If the margin of error in an interval estimate of μ is 4.6, the interval estimate equals b. [pic] 3. The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the c. degrees of freedom 4. The probability that the interval estimation procedure will generate an interval that does not contain the actual value of the population parameter being estimated is the a. level of significance 5. To compute the minimum sample size for an interval estimate of μ, we must first determine all of the following except*…show more content…* .196
28. Refer to Exhibit 8-2. If the confidence coefficient is reduced to 0.80, the standard error of the mean c. remains unchanged
29. Refer to Exhibit 8-2. The 95% confidence interval for the average checkout time of all customers is c. 2.804 to 3.196
Exhibit 8-3
A random sample of 81 automobiles traveling on a section of an interstate showed an average speed of 60 mph. The distribution of speeds of all cars on this section of highway is normally distributed, with a standard deviation of 13.5 mph.
30. Refer to Exhibit 8-3. If we are interested in determining an interval estimate for ( at 86.9% confidence, the z value to use is c. 1.51
31. Refer to Exhibit 8-3. The value to use for the standard error of the mean is d. 1.5
32. Refer to Exhibit 8-3. The 86.9% confidence interval for ( is b. 57.735 to 62.265
33. Refer to Exhibit 8-3. If the sample size was 25 (other factors remain unchanged), the interval for ( would. c. become wider
34. In general, higher confidence levels provide a. wider confidence intervals
35. When the level of confidence increases, the confidence interval b. becomes wider
36. A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to 0.90, the interval for ( a. becomes narrower
37. If we change a 95% confidence interval estimate to a 99% confidence interval