8/13/2019 EXAM MATH 124

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8/13/2019 EXAM MATH 124

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STATISTICS

Directions: Choose only the letter of the correct answer. Show your solution.

1. The number of customers of a servicing center is normally distributed with a mean of P74 and astandard deviation of 8. What percentage of the customers IS between 50 and 98?

A. 99.99% B. 99.7% C. 68% D. 95%

2. A bag contains 6 red marbles, 3 blue marbles and 5 green marbles. If a marble is randomlyselected from the bag, what is the probability that it is blue?

A.11

1 B.

3

1 C.

14

3 D.

5

1

3. A spinner has equal regions numbered 1 through 15. What is the probability that the spinner willstop on an even number or multiple of 3?

A.32 B. 12 C.

31 D.

97

4. How many 3-digit numbers can be formed using digits 1, 2, 3, 4, 5, 6, 7 if repetition is not allowed? A. 343 B. 5 C. 6 D. 210

5. Twelve wrestlers compete with each other. If each wrestlers wrestles one match with otherwrestlers, what are the total number of matches?

A. 66 B. 156 C. 132 D. 78

6. Determine the area under the normal curve:

A. 0.8485 B. 0.8708 C. 0.8907 D. 0.1292

7. Determine the area under the normal curve:

A. 0.9699 B. 0.0301 C. 0.9398 D.0.0602

8. What is the probability that z lies between -0.55 and 0.55.

8/13/2019 EXAM MATH 124

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A. -0.4176 B. -0.9000 C. 0.4176 D. 0.9000

9. Find the IQ score separating the top 14% of the distribution from the others if the mean of thegroup is 100 and a standard deviation of 15.

A. 83.7 B. 104.7 C. 99.8 D. 116.2

10. The lengths of human pregnancies is normally distributed with a mean of 268 days and astandard deviation of 15 days. What is the probability that a pregnancy lasts at least 300 days? A. 0.0179 B. 0.9834 C. 0.0166 D. 0.4834

11. If 45 egg samples have a mean of 1.50 oz and a standard deviation of 0.20 oz, what is thecorresponding standard error?

A. 0.06 oz B. 0.44 oz C. 0.05 oz D. 0.01 oz

12. Construct the 98% confidence interval if the mean is 46.1, standard deviation is 5.7 from asample of 76

A. 44.4 < < 47.8 B. 45.0 < < 47.2 C. 44.8 < < 47.4 D. 44.6 < < 47.6

13. If 48 packages are randomly selected from parcel services and the mean weight is 10.1 poundsand standard deviation of 2.9 pounds. What is the 95% confidence interval for the true mean weight?

A. 93.1 < < 11.1 B. 9.0 < < 11.2 C. 9.3 < < 10.9 D. 9.4 < < 10.8

14. When we find a 99% confidence interval for the mean of the population we know that A. There is a 99% chance that the sample mean is in the interval we find.B. There is a 99% chance that the population mean is in the interval we find.C. 99% of the time we find such a confidence interval, the sample mean is in the interval.D. 99% of the time we find such a confidence interval, the population mean is in the interval.

15. Compute the z-score of 54 from a group with a mean of 60 and standard deviation of 7. A. 0.8571 B. 0.8571 C. 0.5871 D. 0.5871

Directions: Solve the following problems completely.1. How many numbers between 200 and 500 can be formed by using digits 0, 1, 2, 3, 4, 5 if eachdigit must not be repeated in any number?

2. How many different signals can be formed consisting of 6 flags from 4 identical red flags and 2identical blue flags?

3. In how many ways can 9 books be arranged such that 4 books are always together?

4. How many different arrangements can be formed from the letters of the word MISSISSIPPI?

5. In how many ways can a committee of 7 members be selected from 9 male students and 8 femalestudents if each committee must have 4 male students and 3 female students?

Prepared by:

Dr. Romell A. Ramos