The sample size needed to estimate a population mean to within 10 units was found to be 68 . If the ...

The sample size needed to estimate a population mean to within 10 units was found to be 68 . If the population standard deviation was 50, then the confidence level used was:
 a. 99
  b. 95
  c. 90
  d. None of these choices.

Q. 2

One clue to the presence of multicollinearity is an independent variable known to be an important predictor that ends up having a regression coefficient that is not ____________________.
 Fill in the blank(s) with correct word

Q. 3

The sample size needed to estimate a population mean within 2 units with a 95 confidence when the population standard deviation equals 8 is
 a. 62
  b. 61
  c. 8
  d. None of these choices.

Q. 4

An adverse effect of multicollinearity is that the estimated regression coefficients of the independent variables that are correlated tend to have large sampling ____________________.
 Fill in the blank(s) with correct word

Q. 5

To estimate the mean of a normal population whose standard deviation is 6, with a bound on the error of estimation equal to 1.2 and confidence level 99 requires a sample size of at least:
 a. 166
  b. 167
  c. 13
  d. None of these choices.