Statistics

1. The time spent(in days) waiting for a heart transplant in two states for patients with type A+ blood can be approximated by a normal distribution, as shown in the graph to the right. Complete parts (a) and (b) below.

(a) What is the shortest time spent waiting for a heart that would still place a patient in the top 10% of waiting times? Days(round to two decimal places as needed)

(b) What is the longest time spent waiting for a heart that would still place a patient in the bottom 1% of waiting times? Days(round to two decimal places)

The graph is the standard normal curve with the mean=132, standard deviation=18.4 bottom row of the curve to the left is 65 with four spaces then 200 with the variable x over it.

2. Use the normal distribution of SAT critical reading scores for which the mean is 515 and the standard deviation is 113. Assume the variable x is normally distributed.

(a) What percent of the SAT verbal scores are less than 550?

(b) If 1000 SAT verbal scores are randomly selected about how many would you expect to be greater than 525?

(c) Approximately % of SAT verbal scores are less than 550

(d) You would expect that approximately %SAT verbal scores would be greater than 525

3. A survey was conducted to measure the height of men. In the survey, respondents were grouped by age. In the 20-29 age groups, the heights were normally distributed, with a mean of 67.3 inches and a standard deviation of 4.0 inches. A study participant is randomly selected. Complete parts (a) through (c)

(a) Find the probability that his height is less than 68 inches. The probability that the study participant selected at random is less than 68 inches, tall is:

(b) The probability that the study participant selected at random is between 68 and72 inches tall is:

(c) The probability that the study participate selected at random is more than 72 inches tall is:

4. For a sample of n=70 the probability of a sample mean being greater than 230 if the mean = 229 and standard deviation = 3.7 is: (round to four decimal places)

5. Choose one to complete the sentence:

6. Would the given sample would or would not be considered unusual?

7. Because it lies or does not lie within 1Standard deviation, 2 Standard deviations, or 3 Standard deviations

8. Find the indicated probability using the standard normal distribution

P (z<-0.99 or z>0.99) =(round to four decimal places)

9. A vending machine dispenses coffee into a twelve-ounce cup. The amount of coffee dispensed into the cup is normally distributed with a standard deviation of 0.02 ounce. You allow the cup to overfill 3% of the time. What amount should you set as the mean amount of coffee to be dispensed? Ounces.

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