Download 4.1-geometric-review

Statistics
More 4.1-4.2 (with a little 4.3) review
Name: _______________________
In questions 1 – 4, decide whether the random variable x is discrete or continuous. Explain.
1. x represents the number of pumps at a gas station,
2. x represents the weight of a truck at a weigh station.
3. x represents the amount of gas pumped to fill up a car’s gas tank.
4. x represents the number of people on an airplane.
In questions 5 – 8, decide whether the distribution is a probability distribution. If it is not,
explain why.
5. The daily limit per person for catching bass at a certain lake is 4. The random variable x
represents the number of fish caught in one day per person.
x
0
1
2
3
4
p(x) 0.36 0.23
0.08 0.14 0.29
6. The random variable x represents the number of tickets a police officer writes during each shift.
x
0
1
2
3
4
5
p(x) 0.09 0.23 0.29 0.16 0.21 0.02
7. A greeting card shop keeps records of customers’ buying habits. The random variable x
represents the number of cards sold to an individual customer in a shopping visit.
x
1
2
3
4
5
6
7
p(x) 0.68 0.14 0.08 0.05 0.02
0.02
0.01
8. The random variable x represents the number of classes in which a student is enrolled in a given
semester at a university.
x
1
2
3
4
5
6
7
8
p(x)
1
12
27
1
2
1
1
2
10
25
20
5
25
120
80
75
In questions 9 and 10, find the missing probability of the probability distribution.
9.
x
0
1
2
3
4
p(x)
0.24
0.17
?
0.19
0.08
10.
x
p(x)
0
0.12
1
?
2
0.19
3
0.31
4
0.25
For questions 11 and 12, decide whether each experiment is a binomial experiment. If it is
not, explain why. If it is, identify n, p, q, and the values of the random variable x..
11. Bags of plain M & M’s contain 24% blue candies. One candy is selected from each of 12
different bags. The random variable represents the number of blue candies selected.
12. A fair coin is tossed repeatedly until 15 heads are obtained. The random variable counts the
number of tosses.
Find the indicated probabilities. Use the formula or the shortcut on the graphing calculator.
Decide if each experiment is binomial or geometric.
13. One in four adults is currently on a diet. In a random sample of eight adults, what is the
probability that the number currently on a diet is:
a) exactly 3?
b) at least 3?
c) no more than 3?
d) What is the mean and standard deviation of this binomial probability distribution?
14. In a typical day, 31% of people in the U.S. with internet access go online to get news. You ask
people in the U.S. with internet access if they go online to get news. Find the probability that the
first person who says yes is:
a) the second person you ask.
b) before the 5th person.
c) at least the 3rd person.
15. 76% of college students in Michigan receive financial aid. You go to a college campus and
select 15 students at random. Find the probability that the number who receive financial aid is:
a) less than 10?
b) exactly 8?
c) more than 9?
16. 12% of people surveyed claim they just watch the Super Bowl for the commercials. You ask
people if they watch the Super Bowl for commercials. Find the probability that the first person that
says yes is:
a) after the 3rd person.
b) at most the 4th person.
c) the 2nd person.