Statistics 20213 - Introduction to Statistics » Summer 2021 » Test 2 Chapters 4 to 5

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Question #1
Find the indicated probability. The data set represents the income levels of the members of a country club. Find the probability that a randomly selected member earns at least $77,000. Round your answers to the nearest tenth. 93.000 109.000 75,000 117,000 76,000 93,000 77,000 73,000 133,000 173,000 74,000 85,000 125,000 76,000 109,000 101,000 77,000 141,000 72,000 101,000
A.   0.8
B.   0.4
C.   0.7
D.   0.6
Question #2
Use table to summarize the results of the data. In a certain class of students, there are 12 boys from Tarpon Springs, 3 girls from Spring Hill, 9 girls from Tarpon Springs, 7 boys from Brooksville, 2 boys from Spring Hill and 8 girls from Brooksville. If the teacher calls upon a student to answer a question, what is the probability that the student will be a boy?
A.   0.727
B.   0.293
C.   0.512
D.   0.463
Question #3
From the information provided, create the sample space of possible outcomes. Both Fred and Ed have a bag of candy containing a lemon drop, a cherry drop, and a lollipop. Each takes out a piece and eats it. What are the possible pairs of candies eaten?
A.   LD-LD CD-LD LP-LP LD-LP CD-CD LD-LP LP-CD CD-LD LP-LD  
B.   LD-CD LD-CD LD-CD LD-LP LD-LP LD-LP CD-LP  CD-LP CD-LP 
C.   LD-LD CD-LD LP-LP LD-CD CD-CD LD-LP LP-CD CD-LP LP-LD  
D.   CD-LD LD-LP LP-CD LP-LP LD-LD
Question #4
Answer the question. Find the odds against correctly guessing the answer to a multiple choice question with 6 possible answers.
A.   6 : 1
B.   6 : 5
C.   5 : 1
D.   5 : 6
Question #5
Find the indicated complement. Based on meteorological records, the probability that it will snow in a certain town on January 1st is 0.349. Find the probability that in a given year it will not snow on January 1st in that town.
A.   0.651
B.   1.349
C.   2.865
D.   0.536
Question #6
Determine whether the events are disjoint. Get a full time day job as a teller with a bank. Get a full time day job as a cashier at a store.
A.   No
B.   Yes
Question #7
Is Event B dependent or independent of Event A? Event A: You are tall. Event B: You have brown eyes.
A.   Dependent
B.   Independent
Question #8
In one town, 34% of all voters are Democrats. If two voters are randomly selected for a survey, find the probability that they are both Democrats.
A.   0.112
B.   0.680
C.   0.340
D.   0.116
Question #9
Find the indicated probability. A IRS auditor randomly selects 3 tax returns from 40 returns of which 15 contain errors. What is the probability that she selects none of those containing errors? Round to four decimal places.
A.   0.0527
B.   0.2441
C.   0.2328
D.   0.0461
Question #10
Provide a written description of the complement of the given event. Of ten adults, at least one of them has high blood pressure.
A.   Nine of the adults have high blood pressure.
B.   All of the adults have high blood pressure.
C.   Of ten adults, at least one of them has high blood pressure.
D.   None of the adults have high blood pressure.
E.   At most one of the adults has high blood pressure.
Question #11
Find the indicated probability. Round to the nearest thousandth. A study conducted at a certain college shows that 53% of the school's graduates find a job in their chosen field within a year after graduation. Find the probability that among 9 randomly selected graduates, at least one finds a job in his or her chosen field within a year of graduating.
A.   0.530
B.   0.999
C.   0.997
D.   0.111
Question #12
Find the mean of the given probability distribution. The accompanying table shows the probability distribution for x, the number that shows up when a loaded die is rolled. X – P(x) 1-0.15 2-0.10 3-0.13 4-0.11 5-0.13 6-0.38
A.   μ = 0.17
B.   μ = 3.98
C.   μ = 4.11
D.   μ = 3.50
Question #13
Provide an appropriate response. Round to the nearest hundredth. The probabilities that a batch of 4 computers will contain 0, 1, 2, 3, and 4 defective computers are 0.5220, 0.3685, 0.0975, 0.0115, and 0.0005, respectively. Find the standard deviation for the probability distribution.
A.   σ = 0.71
B.   σ = 0.51
C.   σ = 0.93
D.   σ = 0.66
Question #14
A contractor is considering a sale that promises a profit of $32,000 with a probability of 0.7 or a loss (due to bad weather, strikes, and such) of $3000 with a probability of 0.3. What is the expected profit?
A.   $24,500
B.   $21,500
C.   $29,000
D.   $22,400
Question #15
Answer the question. Focus groups of 12 people are randomly selected to discuss products of the Yummy Company. It is determined that the mean number (per group) who recognize the Yummy brand name is 8.8, and the standard deviation is 0.88. Would it be unusual to randomly select 12 people and find that fewer than 5 recognize the Yummy brand name?
A.   No
B.   Yes
Question #16
Determine whether the given procedure results in a binomial distribution. If not, state the reason why. Rolling a single die 53 times, keeping track of the "fives" rolled.
A.   Not binomial: the trials are not independent.
B.   Not binomial: there are more than two outcomes for each trial.
C.   Procedure results in a binomial distribution.
D.   Not binomial: there are too many trials.
Question #17
Find the indicated probability. Round to three decimal places. In a certain college, 33% of the physics majors belong to ethnic minorities. If 10 students are selected at random from the physics majors, that is the probability that no more than 6 belong to an ethnic minority?
A.   0.985
B.   0.913
C.   0.982
D.   0.055
Question #18
Find the indicated probability. Round to three decimal places. A test consists of 10 true/false questions. To pass the test a student must answer at least 9 questions correctly. If a student guesses on each question, what is the probability that the student will pass the test?
A.   0.001
B.   0.011
C.   0.010
D.   0.999
Question #19
According to a college survey, 22% of all students work full time. Find the standard deviation for the number of students who work full time in samples of size 16.
A.   1.7
B.   3.5
C.   2.6
D.   1.9
Question #20
Determine if the outcome is unusual. Consider as unusual any result that differs from the mean by more than 2 standard deviations. That is, unusual values are either less than μ - 2σ or greater than μ + 2σ. A survey for brand recognition is done and it is determined that 68% of consumers have heard of Dull Computer Company. A survey of 800 randomly selected consumers is to be conducted. For such groups of 800, would it be unusual to get 458 consumers who recognize the Dull Computer Company name?
A.   No
B.   Yes

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