Category: Uncategorized

On Halloween, Oprah puts candy out in a bowl – there are 20 Reese’s, 25 Junior Mint boxes, and 15 Laffy Taffys. When the first trick-or-treater comes by, what is the probability they choose a Laffy Taffy?

A sample of n = 4 scores is obtained from a population with µ = 70 and σ = 8.  If the sample mean corresponds to a z-score of 2.00, then what is the value of the sample mean?

A teacher wants to know whether the children in her class are performing significantly better on a standardized math test compared to the national average. The national mean score is μ = 85, the national standard deviation is σ = 25, and the mean score in her class (n = 25) is M = 92.5. Use α = .05. What is the z-score for this sample mean?

Even if a treatment has no effect, it is still possible to obtain an extreme sample mean that is very different from the population mean.  What outcome is likely if this happens?

For a normal population with µ = 40 and σ = 10 which of the following samples has the highest probability of being obtained?

Scores on the SAT form a normal distribution with a mean of µ = 500 with σ = 100.  If the state college only accepts students who score in the top 60% on the SAT, what is the minimum score needed to be accepted?

Anna has 25 jellybeans in a bag. 5 are red, 3 are yellow, 7 are green, and 10 are purple. If Anna picks 4 jellybeans out of the bag without replacing them, and 1 is red, 1 is green, and 2 are purple, what is the probability she picks a yellow jellybean on her next draw?

A random sample of n = 4 scores is obtained from a population with a mean of 80 and a standard deviation of 10.  If the sample mean is M = 90, what is the z-score for the sample mean?

Which of the following is an accurate definition for the power of a statistical test?

A sample of n = 16 scores is selected from a population with µ = 100 and σ = 32.  If the sample mean is M = 104, what is the z-score for this sample mean?