Variable 6 (Time)

80

50

10

40

80

80

10

20

60

80

50

10

80

10

40

80

80

40

80

20

Compute each of the following probabilities, using your calculator and the appropriate methods and formula described in your text, along with the z-tables. Show all your work, including a rough sketch of the appropriate area under the normal curve for each part below.

Problem 8a. Probability that the value of Variable 6 observed will be more than the value which is 1.75 standard deviations above the population mean?

Problem 8b. Probability that the value of Variable 6 observed will be within 1.6 standard deviations of the population mean on either side of the mean?

Problem 8c. Find the two values of Variable 6 such that the middle 40% of all values falls between these two values.