Question 1

A variable is normally distributed with mean 17 and standard deviation 5. Find each of the following probabilities. Give the answer to 4 decimal places as needed. (If you work with the standard normal table, your answer may be preferrable over the answer shown after your last try.) a) P(x 17) = b) P(x 13) = c) P(13 x 21) = d) P(x 20) = e) P(x 19) =

Question 2

Lafyette is deciding which standardized test score to report to the colleges she's applying to. Lafyette took both the SAT and ACT, and wants to report whichever score is higher, relative to the test.

• Lafyette's SAT score was 1190. SAT scores have a mean of 1000 and a standard deviation of 200.
• Lafyette's ACT composite score was 23. ACT scores have a mean of 18 and a standard deviation of 6.

Which score should Lafyette report?

• Lafyette should report her SAT score, because SAT scores are higher overall.
• Lafyette should report ACT score, because it is a better score for the ACT.
• Lafyette should report her SAT score, because it is a better score for the SAT.
• Lafyette should report her ACT score, because ACT scores are lower overall.
• There is not enough information to say.

Question 3

Suppose that a box contains 8 cameras and that 4 of them are defective. A sample of 2 cameras is selected at random. Define the random variable xas the number of defective cameras in the sample. Write the probability distribution for x

x	P(x)

What is the expected value of x?

Question 4 Construct a probability distribution for the given frequency distribution.

(Hint: There were 165 individuals in this sample.)

x	Frequency
200	35
250	6
300	30
350	8
400	22
450	2
500	32
550	8
600	22

Probability Distribution:

x	P(x)
200
250
300
350
400
450
500
550
600

Question 5

An experiment is rolling two fair dice and adding the numbers. State the sample space. S = Find the probability of getting a sum of 6. Round to four decimal places, if necessary. P(6) = Find the probability of getting a sum of 5. Round to four decimal places, if necessary. P(5) = Find the probability of getting a sum of 2 or sum of 9. Round to four decimal places, if necessary. P(2 or 9) = Find the probability of not getting a sum of 7. Round to four decimal places, if necessary. P(not 7) =

Question 6

The maintenance department at the main campus of a large state university receives daily requests to replace fluorecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 39 and a standard deviation of 4. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 39 and 51? Do not enter the percent symbol. ans =

Question 7

Suppose a set of data has mean =16 and standard deviation=1.6.

(Give answers accurate to three decimal places.)

1. What is the z-score for the data value =14? =
2. What is the z-score for the data value =20? =
3. What data value corresponds to the z=score: =2.6? =
4. What data value corresponds to the z=score: =-1.5? =

Question 8

Students in a statistics class were surveyed to see how many pets they own. Below are the results.

Click on the Data button shown below to display the data. Data

(a) Since data were collected for a Select an answer quantitative discrete quantitative continuous qualitative variable(s), what is an appropriate graph to make?

• bar chart
• 2D pie chart
• histogram
• 3D pie chart

(b) Fill out the frequency and relative frequency distribution table.

Number of Pets	Frequency	Relative Frequency
0
1
2
3
4

(c) What proportion of students in this statistics class had at most two pets? (d) What percentage of students in this statistics class had at least two pets?

Question 9