Refer to the following frequency distribution for Questions 1, 2, 3, and 4

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. Just the answer, without supporting work, will receive no credit

.The frequency distribution below shows the distribution for checkout time (in minutes) in UMUC MiniMart between 3:00 and 4:00 PM on a Friday afternoon

.Checkout Time (in minutes) Frequency

1

.0 – 1

.9 5

2

.0 – 2

.9 6

3

.0 – 3

.9 4

4

.0 – 4

.9 3

5

.0 – 5

.9 2

1

. What percentage of the checkout times was less than 3 minutes?

2

. Calculate the mean of this frequency distribution

.3

. Calculate the standard deviation of this frequency distribution

.4

. Assume that the smallest observation in this dataset is 1

.2 minutes

. Suppose this observation were incorrectly recorded as 0

.12 instead of 1

.2

. Will the mean increase, decrease, or remain the same? Will the median increase, decrease or remain the same?

Refer to the following information for Questions 5 and 6

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.A 6-faced die is rolled two times

. Let A be the event that the outcome of the first roll is greater than 4

. Let B be the event that the outcome of second roll is an odd number

.5

. What is the probability that the outcome of the second roll is an odd number, given that the first roll is greater than 4?

6

. Are A and B independent? Why or why not?

Refer to the following data to answer questions 7 and 8

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.A random sample of STAT200 weekly study times in hours is as follows:

4 14 15 17 20

7

. Find the standard deviation

.8

. Are any of these study times considered unusual in the sense of our textbook? Explain

. Does this differ with your intuition? Explain

.Refer to the following table for Questions 9, 10, and 11

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.The table shows temperatures on the first 12 days of October in a small town in Maryland

.Date Temperature Date Temperature Date Temperature

Oct 1 73 Oct 5 53 Oct 9 66

Oct 2 66 Oct 6 52 Oct 10 49

Oct 3 65 Oct 7 62 Oct 11 53

Oct 4 70 Oct 8 55 Oct 12 57

9

. Determine the five-number summary for this data

.10

. Determine the mean temperature

.11

. Determine the mode(s), if any

.Refer to the following information for Questions 12 and 13

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.There are 1000 students in the senior class at a certain high school

. The high school offers two Advanced Placement math / stat classes to seniors only: AP Calculus and AP Statistics

. The roster of the Calculus class shows 100 people; the roster of the Statistics class shows 80 people

. There are 45 overachieving seniors on both rosters

.12

. What is the probability that a randomly selected senior is in at least one of the two classes?

13

. What is the probability that a randomly selected senior takes only one class?

Refer to the following information for Questions 14, and 15

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.A box contains 10 chips

. The chips are numbered 1 through 10

. Otherwise, the chips are identical

.From this box, we draw one chip at random, and record its value

. We then put the chip back in the box

. We repeat this process two more times, making three draws in all from this box

.14

. How many elements are in the sample space of this experiment?

15

. What is the probability that the three numbers drawn are all multiples of 3?

Questions 16 and 17 involve the random variable x with probability distribution given below

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.X 2 3 4 5 6

P(x) 0

.1 0

.2 0

.3 0

.1 0

.3

16

. Determine the expected value of x

.17

. Determine the standard deviation of x

.Consider the following situation for Questions 18, 19 and 20

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.Mimi just started her tennis class three weeks ago

. On average, she is able to return 15% of her opponent’s serves

. Let random number X be the number of serves Mimi returns

. As we know, the distribution of X is a binomial probability distribution

. If her opponent serves 10 times, please answer the following questions:

18

. What is the number of trials (n), probability of successes (p) and probability of failures (q), respectively?

19

. Find the probability that she returns at least 2 of the 10 serves from her opponent

.20

. Find the mean and standard deviation for the probability distribution

.