Suppose nine items are randomly sampled from a normally distributed population with a mean of 100 and a standard deviation of 20. The nine randomly sampled values are:
125 95 66 116 99
91 102 51 110
Calculate the probability of getting a sample mean that is smaller than the sample mean for these nine sampled values.
A) 0.1411
B) 0.1612
C) 0.1512
D) 0.2266
Q. 2Lube-Tech is a major chain whose primary business is performing lube and oil changes for passenger vehicles.
The national operations manager has stated in an industry newsletter that the mean number of miles between oil changes for all passenger cars exceeds 4,200 miles. To test this, an industry group has selected a random sample of 100 vehicles that have come into a lube shop and determined the number of miles since the last oil change and lube. The sample mean was 4,278 and the standard deviation was known to be 780 miles. Based on a significance level of 0.10, the critical value for the test is approximately z = 1.28. Indicate whether the statement is true or false
Q. 3A normally distributed population has a mean of 500 and a standard deviation of 60. Determine the probability that a random sample of size 25 selected from the population will have a sample mean greater than or equal to 515.
A) 0.1056
B) 0.1761
C) 0.0712
D) 0.0151
Q. 4When using the p-value method for a two-tailed hypothesis, the p-value is found by finding the area in the tail beyond the test statistic, then doubling it.
Indicate whether the statement is true or false
Q. 5Six food critics each visited and rated four different restaurants. Each critic visited each restaurant on three separate occasions and recorded a score for each visit. The number of degrees of freedom in the interaction row of the ANOVA table is 15.
Indicate whether the statement is true or false
Q. 6Six food critics each visited and rated four different restaurants. Each critic visited each restaurant on three separate occasions and recorded a score for each visit. The correct method for analyzing this data is two-factor ANOVA.
Indicate whether the statement is true or false
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