Statistics Practice Test 5,6,7
Quiz 5 A card is dealt from a 52-card deck. Find the probability that it is not a 4. Express the probability as a simplified fraction.
12/13
Quiz 5 From 9 names on a ballot, a committee of 5 will be elected to attend a political national convention. How many different committees are possible?
126
Suppose you toss a coin 100 times and get 83 heads and 17 tails. Based on these results, what is the probability that the next flip results in a tail?
17/100
Quiz 6 According to government data, the probability that an adult was never in a museum is 18%. In a random survey of 100 adults, what is the mean and standard deviation of the number that were never in a museum? Round to the nearest thousandth.
18, 3.842
A standard deck of cards contains 52 cards. One card is selected from the deck. Compute the probability of randomly selecting a spade or heart or club.
3/4
Quiz 5 A player is dealt one card from a 52 card deck. Then the card is replaced in the deck, the deck is shuffled, and the player draws again. Find the probability of the player getting a picture card the first time and a diamond the second time. Express the probability as a simplified fraction.
3/52
Compute the probability of randomly selecting a jack or club .
4/13
Quiz 5 A card is drawn from a standard deck of 52 playing cards. Find the probability that the card is a queen or a club. Express the probability as a simplified fraction.
4/13
5.1 Homework, #14 A baseball player hit 53 home runs in a season. Of the 53 home runs, 15 went to right field, 15 went to right center field, 9 went to center field, 8 went to left center field, and went to left field. (a) What is the probability that a randomly selected home run was hit to center field?
9/53
Quiz 5 There are 38 chocolates in a box, all identically shaped. There 14 are filled with nuts, 16 with caramel, and 8 are solid chocolate. Someone randomly selects one piece, eats it, and then selects a second piece. Find the probability of selecting 2 nut candies. Express your answer as a simplified fraction.
91/703
Approximately ____% of the area under the normal curve is between μ -2σ and μ + 2σ.
95
Homework 5.2 #18 According to a survey, the probability that a randomly selected worker primarily drives a bicycle to work is 0.724. The probability that a randomly selected worker primarily takes public transportation to work is 0.088 What is the probability that a randomly selected worker primarily neither drives a bicycle nor takes public transportation to work?
.188
Assume that the random variable X is normally distributed with mean = 80 and Standard deviation = 5. Compute the probability P(x>84). Round to four decimal points
.2119
5.2 Homework #9 Find the probability if P(Ec) if P(E)=0.46. The probability (Ec) is___________________Round to two decimal points
.54
Homework 5.2 #18 According to a survey, the probability that a randomly selected worker primarily drives a bicycle to work is 0.724. The probability that a randomly selected worker primarily takes public transportation to work is 0.088 Determine P(worker drives a bicycle or takes public transportation to work. Round to three decimal points
.812
Quiz 6 According to government data, the probability that an adult was never in a museum is 15%. In a random survey of 10 adults, what is the probability that two or fewer were never in a museum? Round to the nearest thousandth.
.820
Quiz 6 Fill in the blank below. The sum of the probabilities of a discrete probability distribution must be _______.
equal to one
Determine the two z-scores that separate the middle 87.4% of the distribution from the area in the tails of the standard normal distribution.
-1.53, 1.53
Quiz 7 Determine the area under the standard normal curve that lies between the following values. z=0.5 and z=1.4
.2277
5.2 Homework, #7 Find the probability of the indicated event if P(E)=0.30 and P(F)=0.40. Find P(E or F) if P(E and F) =0.10. Round to two decimal points
.60
Quiz 5 The events A and B are mutually exclusive. If P(A)equals 0.2 and P(B)equals 0.3, what is P(A or B)?
0.5
Homework 5.5 #13 How many different simple random samples of size 4 can be obtained from a population whose size is 49? The number of simple random samples which can be obtained is ____________
211,876
Quiz 5 A person can order a new car with a choice of 7 possible colors, with or without air conditioning, with or without heated seats, with or without anti-lock brakes, with or without power windows, and with or without a CD player. In how many different ways can a new car be ordered in terms of these options?
224
Quiz 6 According to a government commission, 70% of the nation's households have VCRs. In a random sample of 15 households, what is the probability that the number of households with VCRs is between 10 and 12, inclusive? Round to four decimal places.
5948
Quiz 7 Approximately___________% of the area under the normal curve is between μ -σ and μ + σ.
68
Quiz 6 Classify the following random variable as either discrete or continuous. The pressure of water coming out of a fire hose
continuous
Quiz 6 Classify the following random variable as either discrete or continuous. The number of bottles of juice sold in a cafeteria during lunch
discrete
Let sample space S =(1, 2, 3, 4, 5, 6, 7, 8) . Suppose the outcomes are equally likely. Compute the probability of the event E equals=(1, 2, 4) .
3/8
Quiz 5 Evaluate the factorial expression. 300!/299!
300
What is the normal density curve symmetric about?
mean
Assume the random variable X is normally distributed, with mean = 40 and standard deviation = 8. Compute the probability P(X<50) Round to four decimal points
.8944
Find the area under the standard normal curve to the left of z=1.25 Round to four decimal points
.8944
Find the area under the standard normal curve to the right of z= -1.25 Round to four decimal points
.8944
Quiz 5 There are 7 performers who are to present their acts at a variety show. How many different ways are there to schedule their appearances?
5,040
Quiz 5 In a contest in which 9 contestants are entered, in how many ways can the 3 distinct prizes be awarded?
504
Quiz 5 Which of the following cannot be the probability of an event? A. -84 B. 0 C. 0.001 D. Sq7/3
-84
Homework 5.3 #6 What is the probability of obtaining seven heads in a row when flipping a coin? Interpret this probability. The probability of obtaining seven heads in a row when flipping a coin is______________Round to 5 decimal points
.00781
Quiz 6 According to insurance records a car with a certain protection system will be recovered 93% of the time. Find the probability that exactly 4 of 7 stolen cars will be recovered. Round to the nearest thousandth.
.009
Homework 5.4 #14 Suppose there is a 27.5 % probability that a randomly selected person aged 20 years or older is a smoker. In addition, there is a 19.9 % probability that a randomly selected person aged 20 years or older is male comma given that he or she smokes. What is the probability that a randomly selected person aged 20 years or older is male and smokes? Would it be unusual to randomly select a person aged 20 years or older who is male and smokes question? Round to 3 decimal places
.055
Quiz 5 Investment in new issues (the stock of newly formed companies) can be both suicidal and rewarding. Suppose that of 300 newly formed companies in 2010, only 11 appeared to have outstanding prospects. Suppose that an investor had selected two of these 300 companies back in 2010. Find the probability that at least one of the investor's companies had outstanding prospects. Round to seven decimal places.
.0721070
Homework 5.5 #14 The grade appeal process at a university requires that a jury be structured by selecting four individuals randomly from a pool of thirteen students and ten faculty. (a) What is the probability of selecting a jury of all students? (b) What is the probability of selecting a jury of all faculty? (c) What is the probability of selecting a jury of two students and two faculty? Round to 4 decimal places
.08075, .02372, .39639
Homework 5.3 #6 About 8% of the population of a large country is allergic to pollen . If two people are randomly selected, what is the probability both are allergic to pollen? What is the probability at least one is allergic to pollen? Round to 4 decimal points
.1536
Quiz 5 Of 1787 people who came into a blood bank to give blood, 379 were ineligible to give blood. Estimate the probability that the next person who comes in to give blood will be ineligible to give blood. Round to three decimal places as needed.
.212
Homework 5.3, #4 Suppose that events E and F are independent, P(E)=0.3, and P(F)=0.8. What is the P(E and F)? The probability P(E and F) is
.24
Quiz 6 A recent article in the paper claims that government ethics are at an all-time low. Reporting on a recent sample, the paper claims that 37% of all constituents believe their representative possesses low ethical standards. Suppose 20 of a representative's constituents are randomly and independently sampled. Assuming the paper's claim is correct, find the probability that more than eight but fewer than 12 of the 20 constituents sampled believe their representative possesses low ethical standards. Round to six decimal places.
.269668
Homework 5.2 #18 According to a survey, the probability that a randomly selected worker primarily drives a bicycle to work is 0.724. The probability that a randomly selected worker primarily takes public transportation to work is 0.088. What is the probability that a randomly selected worker primarily does not drive a bicycle to work?
.276
Quiz 5 At a certain college, 18% of students speak Spanish, 7% speak Italian, and 2% speak both languages. A student is chosen at random from the college. What is the probability that the student speaks Spanish given that he or she speaks Italian? Round your answer to three decimal places.
.286
Homework 5.4 #10 Suppose you just received a shipment of eight televisions. Two of the televisions are defective. If two televisions are randomly selected, compute the probability that both televisions work. What is the probability at least one of the two televisions does not work? (See how problem is solved from my Statistics 2 Test Quizlet) Round to 3 decimal places
.536, .464
Homework 5.3 #6 About 8% of the population of a large country is allergic to pollen. If two people are randomly selected, what is the probability both are allergic to pollen? Round to two decimal points
.64
Homework 5.3 #9 A computer can be classified as either cutting dash edge or ancient. Suppose that 80% of computers are classified as ancient. (a) Two computers are chosen at random. What is the probability that both computers are ancient? (b) Five computers are chosen at random. What is the probability that all five computers are ancient? (c) What is the probability that at least one of five randomly selected computers is cutting dash edge? Round to four decimal places
.6400, .3277, .6723
5.2 Homework, #8 Find the probability P(E or F) if E and F are mutually exclusive, P(E) =0.25, and P(F)=0.45. Round to two decimal points
.70
Quiz 7 The length of time it takes college students to find a parking lot follows a normal deviation with a mean of 4.5 minutes and a standard deviation of 1 minute. Find the probability that a randomly selected college student will take between 3 and 5.5 minutes to find a parking spot in the library lot. Round to 4 decimal places
.7745
Quiz 6 A recent survey found that 70% of all adults over 50 wear sunglasses for driving. In a random sample of 10 adults over 50, what is the probability that at least six wear sunglasses? Round to the nearest thousandth.
.850
Homework 5.3 #7 A test to determine whether a certain antibody is present is 99.5% effective. This means that the test will accurately come back negative if the antibody is not present (in the test subject) 99.5 % of the time. The probability of a test coming back positive when the antibody is not present (a false positive) is 0.005 . Suppose the test is given to seven randomly selected people who do not have the antibody. What is the probability that the test comes back negative for all seven people? What is the probability that the test comes back positive for at least one of the seven people? Round to 4 decimal points
.9655, .0345
Homework 5.3 #7 A test to determine whether a certain antibody is present is 99.5% effective. This means that the test will accurately come back negative if the antibody is not present (in the test subject) 99.5 % of the time. The probability of a test coming back positive when the antibody is not present (a false positive) is 0.005. uppose the test is given to seven randomly selected people who do not have the antibody. a. What is the probability that the test comes back negative for all seven people? b. What is the probability that the test comes back positive for at least one of the seven people? Round to 4 decimal places
.9655, .0365
A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 50 seconds. Find the probability that a randomly selected boy in secondary school will take longer than 335 seconds to run the mile. Round to four decimal points
.9893
Quiz 7 Find the value of za. z0.16 Round to two decimal points
.99
Quiz 7 Suppose a brewery has a filling machine that fills 12 ounce bottles of beer. It is known that the amount of beer poured by this filling machine follows a normal distribution with a mean of 12.18 ounces and a standard deviation of 0.04 ounce. Find the probability that the bottle contains fewer than 12.08 ounces of beer. Round to four decimal places
.9938
Quiz 5 A study conducted at a certain college shows that 58% of the school's graduates move to a different state after graduating. Find the probability that among 7 randomly selected graduates, at least one moves to a different state after graduating. Round to three decimal places as needed.
.998
Quiz 5 Suppose a basketball player is an excellent free throw shooter and makes 90% of his free throws (i.e., he has a 90% chance of making a single free throw). Assume that free throw shots are independent of one another. Suppose this player gets to shoot four free throws. Find the probability that he misses all four consecutive free throws. Round to the nearest ten-thousandth.
0.0001
Which of the following numbers could be the probability of an event? 1, 1.51, 0.03, -0.49, 0, 0.28
1,0.03,0,0.28
Quiz 7 For a standard normal curve, find the z-score that separates the bottom 90% from the top 10%
1.28
Quiz 7 Find the z-score for which the area under the standard normal curve to the left is 0.96
1.75
A standard deck of cards contains 52 cards. One card is selected from the deck. Compute the probability of randomly selecting a spade or heart .
1/2
Quiz 5 A die is rolled. The set of equally likely outcomes is {1,2,3,4,5,6}. Find the probability of getting a 4 .
1/6
Quiz 5 A pool of possible candidates for a student council consists of 13 freshmen and 8 sophomores. How many different councils consisting of 5 freshmen and 7 sophomores are possible?
10,296
Find the z-score for which the area under the standard normal curve to its right is 0.07
148
