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Chapter 4-5-6 Sample Test by Alex
1)
Which of the following cannot be a probability?
A) 0
B).07
C) 1
D)-.051
2)
7 P 3=
A)
337
B)
210
C)
121
D)
1,021
3)
10! /7! =
A)
720
B)
1070
C)
7
D)
740
4)
5 C 2=
A)
120
B)
375
C)
10
D)
20
5)
Is the amount of snowfall discrete or continuous?
A)
Discrete
B)
Continuous
C)
Both A & B
6)
Is the square footage of a house discrete or continuous?
A)
Discrete
B)
Continuous
C)
Both A & B
7)
Is the number of points scored during a basketball game discrete or continuous?
A)
Discrete
B)
Continuous
C)
Both A & B
8)
Seven cards are selected from a standard 52-card deck without replacement. The number of nines
selected is recorded.
Does the probability experiment represent a binomial experiment?
A) No, because the trials of the experiment are not independent and the probability of success differs
from trial to trial.
B)
Yes because the experiment satisfies all the criteria for a binomial experiment.
C)
No, because the experiment is not performed a fixed number of times
D)
No because there are more than two mutually exclusive outcomes for each trial.
9)
An experimental drug is administered to 200 randomly selected individuals, with the number of
individuals responding favorably recorded.
Does the probability experiment represent a binomial experiment?
A)
No, because there are more than two mutually exclusive outcomes for each trial.
B)
Yes, because the trials of the experiment are not independent.
C)
No, because the probability of success differs from trial to trial.
D)
Yes, because the experiment satisfies all the criteria for a binomial experiment.
10) Find the probability of X successes given the probability P of success on a given trial.
N=7, X=7, P=.70
A)
P(7) =.081
B)
P(7) =.083
C)
P(7) =.082
D)
P(7) =.070
11) If we consider an experiment of generating 36 births and recording the genders of the babies, the
mean number of girls is 18 and the standard deviation is 3 girls. Would it be unusual to get 14 girls in 36
births? Why or why not?
A) No, because 14 is below the minimum usual value.
B) Yes, because 14 is greater than the maximum value.
C) Yes, because 14 is within the range of usual values.
D) No, because 14 is within the range of usual values.
12) Given that x has a Poisson Distribution with µ = 9 what is the probability that x=9?
A) .1274
B) .9340
C) .1318
D) .0009
13) A statistics professor plans classes so carefully that the lengths of his classes are uniformly distributed
between 50.0 and 52.0 minutes. Find the probability that a given class period runs less than 50.5 minutes.
A) .25
B) 51.5
C) 50.5
D) .95
14) Use information from Problem 13 above. Find the probability of selecting a class that runs between
51.25 and 51.75
A) .75
B) .95
C) .50
D) .25
15) Assume the readings on thermometers are normally distributed with a mean of 0ºc and a standard
deviation of 100ºC. Find the probability that a randomly selected thermometer reads less than 0.11.
A) .3674
B) -1.254
C) .5439
D) .5438
16) Assume the readings on thermometers are normally distributed with a mean of 0ºc and a standard
deviation of 100ºC. Find the probability P (-.73< Z < .73), where Z is the reading in degrees.
A) .5346
B) .5239
C) .5439
D) 0
17) Pollsters are concerned about declining levels of cooperation among persons contacted in surveys. A
pollster contacts 92 people in the 18-21 age brackets and finds that 49 of them respond and 43 refuse to
respond. When 285 people in the 22-29 age brackets are contacted, 264 respond and 21 refuse to respond.
Suppose that one of the 377 people randomly selected. Find the probability of getting someone in the 2229 age brackets or someone who refused to respond.
P(person is in the 22-29 age bracket or refused to respond) = ________
18) A “Combination” lock is opened with the correct sequence of three numbers between 1 and 73
inclusive. (A number can be used more than once.) what is the probability of guessing those three
numbers and opening the lock with the first try?
19) Assume that a procedure yields a binomial distribution with n trials and the probability of success for
one trial is P. use the given values of n and p to find the mean µ and standard deviation σ. Also use the
range rule of thumb to find the minimum usual value µ - 2σ and the maximum usual value µ + 2σ.
n = 1512, p = ½
µ = ______
σ = ______
µ - 2σ = ________
µ + 2σ = ________
20) Birth weights are normally distributed with a mean of 3420 g and a standad deviation of 495 g. if a
hospital plans to set up special observation conditions for the lightest 4% of babies. What weight is used
for the cut-off seperating the lightest 4% from the others?
The cut-off weight that seperates the lightest 4% of babiesfrom the others is _______g