Test 1 Stats Review
The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. According to the standard deviation rule, almost 2.5% of the students spent more than what amount of money on textbooks in a semester?
$215 Incorrect. The standard deviation rule tells us that for distributions that have the normal shape, approximately 95% of the observations will fall within 2 standard deviations of the mean. The value $215 is 1 standard deviation below the mean.
The distribution of the amount of money spent by first-time gamblers at a major casino in Las Vegas is approximately normal in shape with a mean of 600 dollars and a standard deviation of 120 dollars. According to the standard deviation rule, almost 84% of gamblers spent more than what amount of money at this casino?
$480 Correct. The standard deviation rule tells us that for distributions that have the normal shape, approximately 68% of the observations will fall within 2 standard deviations of the mean. In this case, the mean is $600, and the standard deviation is $120; therefore, approximately 68% of the observations (amount of money spent by gamblers) fall between $600 − 1 * $120 and $600 + 1 * $120 or between $480 and $720. Approximately 100% − 68% = 32% of the observations fall outside this interval. Since the normal shape is symmetric, approximately 16% of the observations fall above $720. Putting this together with the 68% between $480 and $720, a total of 84% of gamblers spend more than $480 at this casino.
When buying a home, the interest rate given on a loan typically depends on the applicant's credit score. The Fair Isaac Corporation (FICO) is a major producer of credit scores. The following table contains 10 randomly selected loan applicants along with their FICO scores and the interest rates that they were given when financing their homes. The linear correlation coefficient between the FICO score and home loan interest rate is: a. - 0.0144 b. 0.9642 c. - 0.9819 d. 0.1723
-0.9819 Correct!
An urn contains 26 red marbles, 31 blue marbles, and 42 yellow marbles. One marble is to be chosen from the urn without looking. What is the probability of choosing a red marble? Your answer should be to rounded to 4 decimal places.
.2626
A club is choosing 2 members to serve on a committee. The club has nominated 1 women and 3 men. Based on chance alone, what is the probability no women are chosen to be on the committee? Your answer should be rounded to 4 decimal places (where applicable).
.50 Correct!
A family plans to have 3 children. For each birth, assume that the probability of a boy is the same as the probability of a girl. What is the probability that they will have at least one boy and at least one girl?
.75 Correct. The outcomes are equally likely, so the easiest way to work this problem is to write out the 8 outcomes in this sample space. In two outcomes the gender of all three children is the same (GGG, BBB). The other 6 outcomes contain at least one boy and one girl.
The distribution of the IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 15. According to the standard deviation rule, only 0.15% of people have an IQ over what score?
145 Feedback Correct. The standard deviation rule tells us that for distributions that have the normal shape, approximately 99.7% of the observations will fall within 3 standard deviations of the mean. In this case the mean is 100, and the standard deviation is 15; therefore, approximately 99.7% of the observations (IQ scores) fall between 100 − 3 * 15 and 100 + 3 * 15 or between 55 and 145. Approximately 100% − 99.7% = 0.3% of the observations fall outside this interval. Since the normal shape is symmetric, approximately 0.15% of the observations fall above 145.
There are 57 students in a Film Production course at GSU: 25 Freshmen, 10 Sophomores, 11 Juniors, and 11 Seniors. One student is selected at random to have his film shown at the Rialto in downtown Atlanta. What is the probability that the chosen student is a Sophomores?
18% Correct. Since there are 10 Sophomores in the course out of a total of 57 students, the probability of selecting one is 10/ 57 = 18 %
Suppose Joan has a fair four-sided die with sides that are numbered 1, 2, 3, and 4. After she rolls it 33 times, Joan finds that she's rolled the number 1 a total of six times. What is the empirical probability that Joan rolls a 1?
18.18% Correct. In six of the 33 different attempts, Joan rolled a 1. So the probability is six / 33 = 18.18 %.
Look at the table below (In order of original table left to right) Score: [40-50), [50-60), [60-70), [70-80), [80-90), [90-100) Count: 1, 3, 3, 5, 2, 2 What percentage of students earned a grade of less than 70?
25% Incorrect. Incorrect. Don't forget that you need to divide the number that is less than 70 by the total number of students/grades. (The correct answer is 44%: 7/16= 43.75)
The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of 369 and a standard deviation of 33. According to the standard deviation rule, approximately 68% of the students spent between _____$ and ______$ on textbooks in a semester.
336$ and 402$ Correct! standard deviation : 68%=1 369+1*33 369-1*33
A 2009 study analyzed data from the National Longitudinal Study of Adolescent Health. Participants were followed into adulthood. Each study participant was categorized as to whether they were obese (BMI >30) or not and whether they were dating, cohabiting, or married. The table below summarizes the results.
34.7% (147/424)
A recent survey asks 82 students, How many hours do you spend on the computer in a typical day? Of the 82 respondents, 1 said 1 hour, 3 said 2 hours, 10 said 3 hours, 20 said 4 hours, 22 said 5 hours, 14 said 6 hours, 7 said 7 hours, 4 said 8 hours, and 1 said 9 hours. In table format, the results look like this: # hours 1 2 3 4 5 6 7 8 9 # students 1 3 10 20 22 14 7 4 1 What is the average (mean) number of hours spent on the computer? Round your answer to one decimal point.
4.9 Correct!
Here are the number of hours that 9 students spend on the computer on a typical day: 4 5 5 5 8 8 10 12 13 What is the mode number of hours spent on the computer?
5 Correct!
Based on the results of a nationwide study, the number of contacts programmed into cell phones are summarized on the following boxplot: Which interval contains the greatest amount of data?
50-100
The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of: μ= 499 and a standard deviation of: σ= 36. According to the standard deviation rule, almost 16% of the students spent more than what amount of money on textbooks in a semester?
535 Correct! 499+1*36
The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 19. According to the standard deviation rule, ______% of people have an IQ between 81 and 119. Do not round.
68% Correct!
An urn contains 40 marbles consisting of 8 red marbles, 28 blue marbles, and 4 yellow marbles. What is the probability of randomly selecting a blue marble from the urn? Answer choices are rounded to the nearest whole percentage.
70% Correct! Since there were 28 blue marbles out of the 40 in the urn, the probability of selecting one is 28/ 40 = 70 %.
The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 12. According to the standard deviation rule, only _____% of people have an IQ over 124.
95%? Feedback Incorrect. The correct answer is: 2.5
Which of the following is an example of stratified sampling?
A health educator wanted to study the sleeping habits of the undergraduate students in her university. For her study, the researcher chose a simple random sample of size 150 from each of the classes (150 freshmen, 150 sophomores, 150 juniors, and 150 seniors) for a total of 600 sampled students. Correct. The researcher viewed the students as being divided into four separate strata (freshmen, sophomores, juniors, and seniors), and a few students from each stratum were selected.
A survey was conducted to study the relationship between a college student's age and the value of the car they drive. Data were collected from a random sample of 300 students from a certain college. The values of the students' cars were found using Kelley Blue Book. Which of the following would be a meaningful display of the data from this study?
A scatterplot
A survey was conducted to study the relationship between the annual income of a family and the amount of money the family spends on entertainment. Data were collected from a random sample of 280 families from a certain metropolitan area. Which of the following would be a meaningful display of the data from this study?
A scatterplot
The city council hired three college interns to measure public support for a large parks and recreation initiative in their city. The interns mailed surveys to 500 randomly selected participants in the current public recreation program. They received 150 responses. In this case, which of the following is the population of interest?
All members of the community
The city council hired three college interns to measure public support for a large parks and recreation initiative in their city. The interns mailed surveys to 500 randomly selected participants in the current public recreation program. They received 150 responses. Which of the following is the appropriate sampling frame in this scenario?
All participants in the city's recreation program Correct. The sampling frame is the list of potential individuals from which the sample gets selected. In this case, that list is participants in the city's recreation program. This is an example in which the sampling frame does not match the population about which the city council wants information.
The faculty senate at a large university wanted to know what proportion of the students thought foreign language classes should be required for everyone. The statistics department offered to cooperate in conducting a survey, and a simple random sample of 500 students was selected from all the students enrolled in statistics classes. A survey form was sent by email to these 500 students. In this case, which of the following is the population of interest?
All students at the university. Correct. The faculty senate wanted to know what proportion of the students supported the proposal. The senate put no restriction on their group of interest, so they want to gauge the opinion of all students at the university.
The faculty senate at a large university wanted to know what proportion of the students thought foreign language classes should be required for everyone. The statistics department offered to cooperate in conducting a survey, and a simple random sample of 500 students was selected from all the students enrolled in statistics classes. A survey form was sent by email to these 500 students. Which of the following is the appropriate sampling frame in this scenario?
All students enrolled in a statistics class Correct. The sampling frame is the list of potential individuals from which the sample gets selected. In this case, that list is restricted to students enrolled in a statistics class. This is an example in which the sampling frame does not match the population that the faculty senate wants information about.
The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. According to the standard deviation rule, how much money did approximately 99.7% of the students spend on textbooks in a semester?
Between $175 and $295 Correct. The standard deviation rule tells us that for distributions that have the normal shape, approximately 99.7% of the observations fall within 3 standard deviations of the mean. Indeed, 175 = 235 − 3 * 20 and 295 = 235 + 3 * 20 are exactly 3 standard deviations below and above the mean, respectively.
The distribution of the IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 15. According to the standard deviation rule, what range of IQ scores do 68% of people have?
Between 85 and 115
The boxplots below show the real estate values of single-family homes in two neighboring cities (in thousands of dollars).
BigBurg Correct. The city whose boxplot appears "longer" is the city whose real estate values had more variability. In this case, Bigburg has more variability, since we see that the Bigburg boxplot extends more on either side than the Tinytown plot.
The boxplots below show the real estate values of single-family homes in two neighboring cities (in thousands of dollars). Which city has the greater percentage of households with real estate values above $85,000?
Both cities have the same percentage of households with real estate values above $85,000.
Suppose that P(A) = 0.95. Which of the following is the best interpretation of this statement?
Event A is extremely likely, but in a long sequence of trials, it occasionally will not occur
Consider the following table summarizing the speed limit of a certain road and the number of accidents occurring on that road in January. 1) Find the slope of the regression line predicting the number of accidents from the posted speed limit.Round to 3 decimal places. 2) Find the intercept of the regression line predicting the number of accidents from the posted speed limit. Round to 3 decimal places. 3) Predict the number of reported accidents for a posted speed limit of 45mph. Round to the nearest whole number.
Feedback Part 1 Correct! Part 2 Incorrect. To find the intercept of the regression line, use the Excel function =intercept(y's,x's) Part 3 Correct!
Given the following summary statistics, determine the regression equation used to predict y from x. sy: 4.84 sx: 4.55 r : 0.69 ¯x: 28.29 ¯y : 74.82 Round all answers to 2 decimal places. slope = y-intercept = Use the exact value of slope when calculating the y-intercept. (literally write out the entire slope from the calculator)
Feedback Part 1 Correct! Part 2 Incorrect. To find the y-intercept of the regression equation, use -y - b-x The correct answer is 54.06.
Suppose that the regression for predicting weight (in pounds) from Height (in inches) is given by Weight = -115 + 3.6(Height) Which of the following statements is correct? I. A person who is 61 inches tall will weigh 104.6 pounds. II. For every additional inch of height, the predicted weight will increase, on average, by 3.6 pounds. III. The correlation between weight and height is negative.
II only
The weights (in pounds) and cholesterol levels (in mg/dL) of several individuals was observed. The data are shown in the scatterplot below: The outlier on the graph is likely due to an error in recording the data. Which of the following statements is true?
If the outlier were removed, the correlation coefficient (r) would increase.
The boxplots below show the real estate values of single-family homes in two neighboring cities (in thousands of dollars).
It is impossible to tell from the boxplots. Correct. A boxplot only displays the five-number summary of a dataset. A boxplot doesn't indicate how many data values might have been in the dataset. So, in this case, the boxplots only indicate the income levels for the households in the city, but not how many households there might be in the city
Suppose Joan has a fair four-sided die with sides that are numbered 1, 2, 3, and 4. Image attribution:CC BY NC 3.0byCK-12 After she rolls it 20 times, how many times does she roll the number 3?
It is impossible to tell.
Suppose Joan has a fair four-sided die with sides that are numbered 1, 2, 3, and 4. After she rolls it 2,000 times, she finds that she rolled the number 2 a total of 187 times. Which of the following is true?
Joan has provided evidence that calls into question whether or not this is a fair die because the relative frequency of rolling a 2 is quite different than the theoretical probability even after repeating the experiment many times.
The boxplots below show the number of marshmallows in a bag, as estimated by students in two elementary school classes. Which class has greater variability in students' estimate of the number of marshmallows?
Ms. Apple's Class Correct. The class whose boxplot appears "longer" is the class whose real estate values had more variability. In this case, Ms. Apple's class has more variability, since we see that the boxplot for her class extends more on either side than the boxplot for Ms. Banana's class.
The boxplots below show the number of marshmallows in a bag, as estimated by students in two elementary school classes. Which class has more students?
Ms. Apple's Class Incorrect. A boxplot only displays the five-number summary of a dataset. A boxplot doesn't indicate how many data values might have been in the dataset. So, in this case, the boxplots indicate the students' estimates, but not how many students are in each class. (Correct guess: It is impossible to tell)
The boxplots below show the number of marshmallows in a bag, as estimated by students in two elementary school classes. Which class has a greater percentage of estimates between 50 and 100 marshmallows?
Ms. Banana's Class Correct. In fact, the percentage of estimates between 50 and 100 is exactly 50% since this is the percentage of scores between the minimum value (50) and the median (100), while we can reason that less than 50% of Ms. Apple's class gave estimates in this same range.
The boxplots below show the number of marshmallows in a bag, as estimated by students in two elementary school classes. Which class has the greater percentage of estimates over 100?
Ms. banana's class Feedback Correct. Notice the line inside each box. The line marks the median of the data. So in this case, exactly 50% of the students in Ms. Banana's class had estimates over 100. Ms. Apple's class had fewer than 50% with estimates over 100 because the median for her class was 75.
In order to obtain a sample of undergraduate students in the United States, a simple random sample of 10 states is selected. From each of the selected states, 10 colleges or universities are chosen at random. Finally, from each of these 100 colleges or universities, a simple random sample of 20 undergraduate students is selected. Thus, the final sample consists of 2,000 undergraduates. This is an example of which type of sampling strategy?
Multistage sampling
It is known that 4% of children carry a certain virus, but a leading health researcher suspects that the percentage is actually higher. Which of the following provides the most convincing evidence to support the researcher's suspicion?
Out of 5,000 randomly chosen children, 250 children carry the virus.
It is known that roughly 5% of the general population carry a certain virus. A health researcher believes that among caucasian males the percentage is actually lower. Which of the following will provide the most convincing evidence to support the researcher's suspicion?
Out of 6,000 randomly chosen caucasian males, 240 males carry the virus. Correct. The relative frequency of caucasian males carrying the virus is 240/6,000 = 0.04 = 4% which is less than 5%.
A recent survey asks 94 students, How many hours do you spend on the computer in a typical day? Of the 94 respondents, 3 said 1 hour, 9 said 2 hours, 19 said 3 hours, 21 said 4 hours, 16 said 5 hours, 12 said 6 hours, 8 said 7 hours, 5 said 8 hours, and 1 said 9 hours. In table format, we have the following: # hours 1 2 3 4 5 6 7 8 9 # students 3 9 19 21 16 12 8 5 1 What is the average (mean) number of hours spent on the computer? Round your answer to one decimal point. What is the median number of hours spent on the computer?
Part 1 Incorrect. 4.5 The mean is the sum of the measurements divided by the number of measurements. For the sum, each time a measurement occurs, it is added. To find the sum of the computer hours, use the SUMPRODUCT Excel function. Use the SUM Excel function to sum the numbers of students in the second row of the table. Part 2 Incorrect. 4 The median is the value in the middle position of the ordered measurements. For an even number of measurements, the middle position is the (n+1)/2 th measurement. Since this is not a whole number, we will take the average of the measurements in the 2 middle positions. The middle positions are the n/2 and n/2 + 1 positions. Using the SUM Excel function for the second row in the table, the number of students is found to be 94. 94/2 = 47 94/2 + 1= 48 The average of the 47th and 48th measurements is 4
A student survey was conducted at a major university, and data were collected from a random sample of 750 undergraduate students. One variable that was recorded for each student was the student's answer to the question "With whom do you find it easiest to make friends? Opposite sex/same sex/no difference." These data would be best displayed using which of the following?
Pie chart
A local ice cream shop kept track of the number of cans of cold soda it sold each day, and the temperature that day, for 2 months during the summer. The data are displayed in the scatterplot below:
Positive linear relationship with outlier(s)
The following scatterplot shows the relationship between the amount of money spent (budget) and the amount of money earned (gross) for the 13 Hollywood movies with the highest profit.
Positive nonlinear relationship
Which of the following is an example of stratified sampling?
Proponents of a local ballot measure conduct a survey of the city by randomly selecting 100 potential voters from each of its 18 zip codes.
Based on the results of a nationwide study, the number of contacts programmed into cell phones are summarized on the following boxplot: Choose the correct label for the point on the boxplot represented by the question mark:
Q3
The histogram below displays the distribution of 50 ages at death due to trauma (accidents and homicides) that were observed in a certain hospital during a week. Which of the following best describes the shape of the histogram?
Right-skewed with a possible outlier Feedback Correct. The distribution of ages is skewed right (which is where the "tail" of the distribution is). Also, the largest observation—approximately equal to 90—is a possible high outlier.
A person trying to gain access to a bank vault must pass through a series of three security doors. If an attempt to pass through a door is a failure, then the person will not make any further attempts. Let P denote a successful pass and F denote a failed pass. What is the sample space for this random experiment?
S = {F, PF, PPF, PPP}
In order to study whether IQ level is related to birth order, data were collected from a sample of 540 students on their birth order (Oldest/In Between/Youngest) and their score on an IQ test. Which of the following would be a meaningful display of the data from this study?
Side by Side box plots
The boxplots below display annual incomes (in thousands of dollars) of households in two cities. Which city has greater variability in income?
Statstown Correct. The city whose boxplot appears "longer" is the city whose incomes had more variability. In this case, Statstown has more variability, since we see the Statstown boxplot extends more on either side than the Medianville plot.
Which of the tables is the appropriate table of conditional percentages to discover if the region where one lives affects whether or not one has health insurance?
Table A
An instructor asked her students how much time (to the nearest hour) they spent studying for the midterm. The data are displayed in the following histogram: What do the numbers on the vertical axis represent?
The count of students falling in each of the intervals. Correct!
The cost of taking your pet aboard the air flight with you in the continental US varies according to the airlines. The five number summary for prices based on a sample of major U.S. airlines was: Min = 60, Q1 = 100, Median = 110, Q3 = 125, Max = 150 Which of the following is true about this data?
The lowest price is an outlier.
Suppose the correlation between two variables (x, y) in a data set is determined to be r = 0.8, What must be true about the slope, b, of the least-squares line estimated for the same set of data?
The slope will have the same sign as the correlation
An instructor asked her students how much time (to the nearest hour) they spent studying for the midterm. The data are displayed in the following histogram: What do the numbers on the horizontal axis represent?
The values of the number of hours studied. Correct!
The data in the scatterplot below are an individual's age (in years) and the expected life span (in years). The circles correspond to females and the x's to males. Which of the following conclusions is most accurate?
There is a negative correlation between age and life expectancy for both males and females.
The boxplots below show the real estate values of single-family homes in two neighboring cities (in thousands of dollars). Which city has a greater percentage of homes with real estate values between 55,000 dollars and 85,000 dollars?
Tinytown Correct. Values between 55,000 dollars and 85,000 dollars include less than a fourth of the homes in Bigburg but more than a fourth of the households in Tinytown because of how the medians and the first quartiles compare for the two cities.
When conducting a survey, which of the following is the most important reason to use a random sample?
To avoid bias and to get a representative sample
A store asked 250 of its customers whether or not they were satisfied with the service (yes or no). The responses were also classified according to the gender of the customers. We want to study whether there is a relationship between satisfaction and gender. Which of the following would be a meaningful display of the data from this study?
Two- way table
A researcher wants to determine if preschool attendance is associated with high school graduation for low-income students. She randomly assigns low-income children to two groups; one group will attend the preschool program, and the second group will not attend preschool. The researcher plans to follow the children in the study for 20 years and observe whether or not they graduate from high school. Which of the following is the response variable in this study?
Whether or not a subject graduates high school
A researcher wants to determine if preschool attendance is associated with high school graduation for low-income students. She randomly assigns low-income children to two groups; one group will attend the preschool program, and the second group will not attend preschool. The researcher plans to follow the children in the study for 20 years and observe whether or not they graduate from high school. Which of the following is the explanatory variable in this study?
Whether or not the subject attends preschool
A study is conducted to determine the effect of television violence on men. A random sample of 500 men was selected and a survey was administered to determine if the men watched high or low levels of TV violence as children and if they were physically abusive (hit, grabbed, or shoved) towards their partners as adults. Which of the following would be a meaningful display of the data from this study?
a two-way table
A survey was conducted to see how many phone calls people made daily. The results are displayed in the table below: Number of calls made: 1-4, 5-8, 9-12, 13-16, 17-20 Frequency: 18, 10, 6, 3, 1 Round all answers to the nearest whole number. How many of the people surveyed make less than 5 calls per day? What percentage of those surveyed make at least 9 calls per day? % How many people were surveyed?
a. 18 b. 47% (18ppl who made less than 5 calls/38) c. 38
A study seeks to answer the question, "Does Vitamin C level in the breast milk of new mothers reduce the risk of allergies in their breastfed infants?" The study concluded that high levels of vitamin C (measured in milligrams) were associated with a 30 percent lower risk of the presence of allergies in the infants. In this scenario, "presence of allergies" is what type of variable?
categorical
What type of variable is region?
categorical Correct!
In order to get people's opinions about a particular Supreme Court decision a reporter interviewed 30 people who have gathered outside the courthouse waiting for the announcement. The reporter makes sure to question people who have signs expressing a variety of positions on the issue. This is an example of which type of sampling strategy?
convenience sampling Correct. Convenience samples contain people who happen to be at the right place at the right time for the convenience of the person doing the sampling.
he faculty senate at a large university wanted to know what proportion of the students thought foreign language classes should be required for everyone. The statistics department offered to cooperate in conducting a survey, and a simple random sample of 500 students was selected from all the students enrolled in statistics classes. A survey form was sent by email to these 500 students. True or false? Since the sample is random, it is representative of the population of interest.
false Correct. Although the 500 survey recipients were selected randomly from some larger sampling frame, the study is not representative of the intended population of all students at the university because (1) the sampling frame was only students in statistics (so the sampling frame didn't match the population of interest), and (2) returning the survey was voluntary (so the study results were potentially biased and thus not representative, even of just statistics students).
When conducting a survey, which of the following is the most important reason to avoid using a volunteer sample?
our conclusions could not be reliably generalized to a larger population
A study seeks to answer the question, "Does Vitamin C level in the breast milk of new mothers reduce the risk of allergies in their breastfed infants?" The study concluded that high levels of vitamin C (measured in mg) were associated with a 30 percent lower risk of allergies in infants. In this scenario, "levels of vitamin C (measured in milligrams)" is what type of variable?
quantitative
What can we say about the relationship between the correlation r and the slope b of the least-squares line for the same set of data?
r and b have the same sign (+ or -).
In order to study whether there is a relationship between gender and age at marriage, 50 couples were randomly selected and the age of the bride and groom were recorded. Which of the following would be a meaningful display of the data from this study?
side by side box plots
The city council hired three college interns to measure public support for a large parks and recreation initiative in their city. The interns mailed surveys to 500 randomly selected participants in the current public recreation program. They received 150 responses. True or false? Even though the sample is random, it is not representative of the population of interest.
true Correct. While the selection of subjects was random, subjects were not representative of the population of the city because only participants in the recreation program were included in the sample. Also, there was a large non-response rate.
A couple decides to have three children. Let A define the event that the couple has at least 1 girl. What are the possible outcomes for this event? (G=girl, B=boy) a. {G, BG, BBG} b. {G, GG, GGG} c. {BBB, BBG, BGB, GBB, GGB, GBG, BGG, GGG} d. {GGG, GGB, GBG, BGG, GBB, BGB, BBG} e. {GBB, BGB, BBG}
{GGG, GGB, GBG, BGG, GBB, BGB, BBG} Correct. Event A is all outcomes in the sample space except BBB.
A person must enter a 4 digit code to gain access to his cell phone. He will enter codes until he is successful, however he cannot try more than 3 times or the phone will lock him out. Let S denote a successful attempt and F denote a failed attempt. What is the sample space for this random experiment?
{S, FS, FFS, FFF} Correct. The person stops trying when he successfully enters the code or when he has failed at all 3 attempts.
A person in a casino decides to play blackjack until he wins a game, but he will not play more than 3 games. Let W denote a win and L denote a loss. What is the sample space for this random experiment?
{W, LW, LLW, LLL} Correct. The person stops playing when he wins or if he plays three games without winning.
A person in a casino decides to play 3 games of blackjack. Let W denote a win and L denote a loss. Define the event A as "the person wins at least one game of blackjack." What are the possible outcomes for this event?
{WWW, WWL, WLW, WLL, LWW, LWL, LLW} Correct. Event A is all outcomes in the sample space except LLL.
