SDS Statistics and probability

The mean of 12, 15, 11, 18 and 14 is:

• 1 14.0
• 2 15.0
• 3 12.0
• 4 13.5

Which measure of central tendency is least affected by an extreme outlier?

• 1 Mean
• 2 Range
• 3 Variance
• 4 Median

A correlation coefficient of -0.9 between two variables means:

• 1 A strong negative linear relationship
• 2 A weak positive relationship
• 3 No relationship
• 4 One causes the other

A p-value of 0.03 at a 5 percent significance level leads to:

• 1 Proving the alternative is true
• 2 Rejecting the null hypothesis
• 3 No conclusion
• 4 Accepting the null hypothesis as true

Rejecting a null hypothesis that is actually true is a:

• 1 Type I error
• 2 Rounding error
• 3 Sampling error only
• 4 Type II error

2 percent of invoices are fraudulent. A test flags 90 percent of fraudulent and 5 percent of genuine invoices. The probability that a flagged invoice is fraudulent is closest to:

• 1 2%
• 2 95%
• 3 27%
• 4 90%

The expected value of an action with a 60 percent chance of $10,000 and a 40 percent chance of -$5,000 is:

• 1 $5,000
• 2 $2,000
• 3 $6,000
• 4 $4,000