8.9 Review

To find the probability that the mean amount of weight lost by 15 people is no more than 14 pounds, the random variable should be:

• A The number of people who lost weight on the special weight loss diet
• B The number of people who were on the diet
• C The mean amount of weight lost by 15 people on the special weight loss diet
• D The total amount of weight lost by 15 people on the special weight loss diet

Find the probability asked for in the previous problem.

Find the 90th percentile for the mean amount of weight lost by 15 people.

What is the probability that the time of occurrence is within the first half-hour or the last hour of the period from 4 to 7 p.m.?

• A Cannot be determined from the information given
• B $\frac{1}{6}$
• C $\frac{1}{2}$
• D $\frac{1}{3}$

The 20th percentile occurs after how many hours?

• A 0.20
• B 0.60
• C 0.50
• D 1

Assume Ramon has kept track of the times for the first accidents to occur for 40 different days. Let $C$ = the total cumulative time. Then $C$ follows which distribution?

• A $U(\mathrm{0,3})$
• B $\text{Exp}(\frac{1}{3})$
• C $N(\text{60},\text{5.477})$
• D $N(1\text{.}\mathrm{5,0}\text{.}\text{01875})$

Using the information in question #6, find the probability that the total time for all first accidents to occur is more than 43 hours.

How long must a parent expect to wait for his children to clean their rooms?

• A 8 days
• B 3 days
• C 14 days
• D 6 days

What is the probability that a parent will wait more than 6 days given that the parent has already waited more than 3 days?

• A 0.5174
• B 0.0174
• C 0.7500
• D 0.2143

Find the probability that a randomly chosen student at the local community college does not live within five miles of the campus.

• A 80%
• B 20%
• C 30%
• D Cannot be determined

Find the probability that a randomly chosen student at the local community college lives within five miles of the campus or receives some kind of financial aid.

• A 50%
• B 35%
• C 27.5%
• D 75%

Based upon the above information, are living in student housing within five miles of the campus and receiving some kind of financial aid mutually exclusive?

• A Yes
• B No
• C Cannot be determined

The interest rate charged on the financial aid is _______ data.

• A quantitative discrete
• B quantitative continuous
• C qualitative discrete
• D qualitative

What follows is information about the students who receive financial aid at the local community college.

• 1st quartile = $250
• 2nd quartile = $700
• 3rd quartile = $1200

(These amounts are for the school year.) If a sample of 200 students is taken, how many are expected to receive $250 or more?

• A 50
• B 250
• C 150
• D Cannot be determined

$P(A\text{AND}B)=$

• A 0.5
• B 0.6
• C 0
• D 0.06

$P(A\text{OR}B)=$

• A 0.56
• B 0.5
• C 0.44
• D 1

If $H$ and $D$ are mutually exclusive events, $$ $P(H)=0\text{.}\text{25}$ , $P(D)=0\text{.}\text{15}$ , then $P(H|D)$

• A 1
• B 0
• C 0.40
• D 0.0375