20 Assume that ages of college level statistic students foll

20.

Assume that ages of college level statistic students follow a bell-shaped (normal) distribution with a mean of 26

years and a standard deviation of 6.2 years.

a.

Based upon the Empirical (68-95-99.7) Rule, give an interval that will contain 95% of all such ages.

b.

What would be the z-score (standard score) of a college statistics student that is 35 years old?

c.

If the z-score of a college statistics students was stated to be ?1.25, what would be her/his age?

21.

A nurse measured the blood pressure of each patient who visited his clinic during the last month. At the right is a relative-frequency histogram for the systolic blood pressure readings for those between 25 and 40 years old. Use the histogram to answer the following questions.

a.

Reasonably approximate the median blood pressure reading.

b.

Approximate the percentage of patients measured who had a systolic blood pressure reading higher than 130?

c.

What woud be the probability of selecting one of the patients and their reading was lower than 120?

22.

Designate the correct statistical term for each of the following symbols in the space to its right,

this includes designating which are population measures and which are sample measures.

23.

A certain zoo is know to collect \"unusual\" animals from different animal groups.

One ostrich specimen in the zoo weighs 229 kg and one elephant specimen weighs 8150 kg.

Which of these two specimens would be considered more unusual in their group if ostriches

have mean weight of 178.4 kg and a standard deviation of 21.3 kg, while elephants have a mean

weight of 7250.6 kg with a standard deviation of 423.4 kg.  

(Quantitative measures leading to your conclusion must be shown for credit . . . guessing does not count.)

24.

Describe what is implied when a student has a standard score (z-score) of 0 on an exam.

25.

Assume you have a group of seven ping-pong balls numbered from one to seven. Let us define some events as follows:

Event A: A randomly selected ball is marked with an odd number

Event B: A randomly selected ball is marked with an even number

Event C: A randomly selected ball is marked with either a five, a six, or a seven

Answer the following questions related to probability of the above described events

for a SINGLE random selection of one ping-pong ball:

(Recall that this is asking,\"What is the probability that a randomly selected ball has an odd number on it?\")

a.

P(A) =

(Recall that this is asking,\"What is the probability that a randomly selected ball has an odd number on it?\")

b.

P(B) =

c.

P(A and B) =

d.

P(A or C) =

e.

P(not C) =

f.

P(C given B) =

g.

Describe the complement of Event C.

h.

From the 3 events listed above (Events A, B, & C), give one pair which IS mutually exclusive?

Explain your answer.

26.

A local organization is having a raffle drawing to give away three $500 gift certificates. If 280 people enter the raffle by each buying one ticket, how many different groups of three winners can there be?

27.

The data in the accompanying table at the right compares tattoos and smoking of tobacco for a randomly selection of 500 men. Use the two-way table data to answer the following questions.

a.

If one of these men is randomly selected, find the probability the man will be a tobacco smoker.

b.

Find the probability of randomly selecting a man from this group that is not smoker, given that the man has more than two tattoos.

c.

Determine the percentage of men in the group who are not smokers and had at one or two tattoos.

No Tattoo

One or Two Tattoos

More than Two Tattoos

Does not Smoke Tobacco

185

135

14

Smokes Tobacco

61

55

50

20.	Assume that ages of college level statistic students follow a bell-shaped (normal) distribution with a mean of 26 years and a standard deviation of 6.2 years.
	a.	Based upon the Empirical (68-95-99.7) Rule, give an interval that will contain 95% of all such ages.
	b.	What would be the z-score (standard score) of a college statistics student that is 35 years old?
	c.	If the z-score of a college statistics students was stated to be ?1.25, what would be her/his age?

Solution

20 a) (19.8, 32.2)

b) 1.45

c) 26-1.25(6.2) = 18.25

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22) HIstogram missing.

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23)

24) He got average score.

25)

26) 500C282 ways

27)a) 166/500= 0.332

b) 14/64 = 0.2188

c) 135/500 = 0.270