• Think about a density curve that consists of two line segments. The first goes from the point (0, 1) to the point (0.4, 1). The second goes from (0.4, 1) to (0.8, 2) in the xy-plane. What percent of observations fall below 0.40?

• Think about a density curve that consists of two line segments. The first goes from the point (0, 1) to the point (0.4, 1). The second goes from (0.4, 1) to (0.8, 2) in the xy-plane. What percent of observations fall between 0.4 and 0.8?

• Consider a uniform density curve defined from x = 0 to x = 6. What percent of observations fall below 5?

• Consider a uniform density curve defined from x = 0 to x = 7. What percent of observations fall between 1 and 5?

• Consider a spinner that, after a spin, will point to a number between zero and 1 with uniform probability. Determine the probability: P(¹₆ X ¹₂).

• The heights of students in a class are normally distributed with mean 66 inches and standard deviation 5 inches. Use the Empirical Rule to determine the interval that contains the middle 95% of the heights.

• The length of time needed to complete a certain test is normally distributed with mean 74 minutes and standard deviation 12 minutes. Find the probability that it will take less than 88 minutes to complete the test.

• If X is normally distributed with a mean of 30 and a standard deviation of 2, find P(30 X 33.4).

• Suppose that X is normally distributed with a mean of 60 and a standard deviation of 3. What is P(X 64.05)?

• Suppose that x is normally distributed with a mean of 50 and a standard deviation of 4. What is P(x 57.80)?

• Suppose that x is normally distributed with a mean of 20 and a standard deviation of 6. What is P(13.82 x 29.18)?

• At a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 76 and a standard deviation of 14. The scores on the calculus final are also approximately normally distributed, with a mean of 74 and a standard deviation of 15. A student scored 79 on the chemistry final and 81 on the calculus final. Relative to the students in each respective class, in which subject did the student do better?

• Find a value of c so that P(Z c) = 0.76.