WGU C207 Data Driven Decision Making Module 2 Exam (Answered)

WGU C207 Data Driven Decision Making Module 2 Exam (Answered) Which of the following is NOT an application of statistics in business? a Determine the internet advertiser that will reach the most people from extensive page view data. b Determine a target market based on information on household incomes throughout the country. c Predict trends in certain investments of big companies from previous results of Fortune 100 companies. d Forecast likelihood of board of director decisions from previous voting habits. d Forecast likelihood of board of director decisions from previous voting habits. Although this might be in a business context, this is the use of statistics in politics. The other three examples are applications of statistics in business. Bethany notices that her husband is wearing a blue sweater on Tuesday. She cannot remember what he has worn previous Tuesdays. The next Tuesday she notices he is wearing another blue sweater. She concludes that if it is Tuesday, he will wear a blue sweater having data from her experiment to support this. What is the flaw with this experiment? a Small Sample Size b Operationalization c Missing Data d Assumptions a Small Sample Size This is an experiment with too few data entries to form a statistically relevant conclusion. Doctor Andrews has been trying to measure the likelihood of heart attack risk. Doctor Andrews decides to monitor hair length in people to determine those at high risk of heart attack. What is the flaw in this experiment? a Assumptions b Association vs. Causation c Response Bias d Operationalization d Operationalization Monitoring hair growth does not measure the risk of heart attack. There is a flaw in the experiment because the experiment is not measuring what the objective is trying to determine. Mr. Wonka notices that the last twenty times he invented a new chocolate candy, his major competitors, Count Chocula, and the Easter Bunny, have big sales in late October. Mr. Wonka feels directly responsible for the profit of his competitors. What is the flaw in this experiment? a Small Sample Size b Truly Representative Sample c Association vs. Causation d Blinding c Association vs. Causation Mr. Wonka's inventive ways are probably not the cause of increased chocolate candy sales for his competitors at the end of October like Mr. Wonka has concluded. There is a 90 percent chance that a package will arrive within three days of when it was shipped. Also, there is a 75 percent chance that it will get wet. There is a 70 percent chance that it will get wet and will be delivered within three days. What is the likelihood that at least one of these events occurs? a 0.8 b 0.85 c 0.9 d 0.95 d 0.95 This is a union between P(on time) and P(wet). Therefore, P(on time∪wet) =P(on time)+P(wet)−P(on time∩wet) =0.90+0.75−0.70=0.95=95% There is an 80 percent chance of snow. If it snows there is a 10 percent chance of Todd walking to the store. If it doesn't snow there is a 60 percent chance of Todd walking to the store. What is the likelihood that it will not snow and Todd will walk to the store? a 0.12 b 0.18 c 0.2 d 0.48 a 0.12 The probability of no snow is 20 percent ( P(no snow)=0.20 ), and the probability of Todd walking to the store with no snow is 60 percent ( P(walk|no snow)=0.60 ). Therefore to determine the likelihood of it not snowing and Todd walking to the store, these probabilities are multiplied together. Therefore P(no snow∩walk)=P(no snow)×P(walk|no snow)= 0.20×0.60=0.12=12% Determine the Mode, Median, Mean (in that order) from the following data set. 4, 7, 11, 12, 14, 14, 15, 17, 17, 17, 18, 20, 23, 24, 26, 29, 35, 39, 40 a 17, 17, 20 b 14, 17.5, 17 c 17, 17, 17 d 17, 17, 20.11 d 17, 17, 20.11 The mode is 17 as it shows up 3 times and no other data point shows up as many times. The median is 17 as it is the 10th number out of 19 ordered numbers. The mean is 20.11 as it is the result of the sum of the numbers, 382, divided by 19, the count of numbers. Standard deviation measures a the average of the difference for the data set. b the normal exceptions between the expected data points. c the median of the data set distributed equally. d the dispersion from the average for the data set. d the dispersion from the average for the data set. Elizabeth got a 75 on her performance review. The average was 80, but the standard deviation was 3.5. Determine the z-score for her performance review. a 1.43 b -1.43 c 5 d 3.5 b -1.43 This is because she was 1.43 standard deviations below the average. Z-score is determined by the distance a data point is from the mean divided by the standard deviation. The data point was five below the mean ( therefore -5), and the standard deviation was 3.5. Therefore, the z-score for Elizabeth's performance review was −53.5=−1.43 . Statistical analysis can be used to make __________ about entire populations using samples. a) conclusions b) inferences c) decisions d) references b) inferences What percent of the data of a normal distribution is within two standard deviations of the mean? a) 68.3 b) 75 c) 95.4 d) 99.7 c) 95.4 Judy is a big supporter of her local police force. A surveyor from the city government calls to conduct a poll about her satisfaction with the police in her community. Judy gives overwhelmingly positive answers to the questions, even if she thinks there are some areas for improvement. What kind of bias is Judy introducing? a) response bias b) conscious bias c) gender bias d) retrospective adjustment a) response bias What is the interquartile range of the following numbers? 5, 9, 14, 25, 32, 36, 37, 37, 43, 48, 51 a) 12 b) 41 c) 29 d) 46 c) 29 The interquartile range for these numbers is 29. The 75th percentile is 43, and the 25th percentile is 14. Subtracting 14 from 43, we arrive at 29. What is the mean of the following data set? 9, 7, 23, 20, 4, 6, 26, 5, 21, 14 a) 13.5 b) 12 c) 26 d) 14 a) 13.5 The mean is the same as the average, which we get by adding up the values of each data point and dividing by the number of data points. There are 10 data points that add up to 135. 135/10=13.5 . Which of the following numbers is closest to the 70th percentile? 3, 4, 5, 6, 7, 9, 10, 14, 20, 21, 23, 26, 65 a) 65 b) 20 c) 26 d) 14 b) 20 The number 20 in this series of numbers is the closest value to the 70th percentile. There are 13 numbers, and therefore the 70th percentile would be at the 9.1th number in the series (from small to large). The 9th number in that series is 20. If a man owns two sports cars, two luxury cars, and one SUV, what is the probability that he'll take a luxury car when he goes out tonight? a) 2/5 b) 1/5 c) 5/2 d) 3/5 a) 2/5 If a man owns two sports cars, two luxury cars, and one SUV, what is the probability that the man will not take a luxury car out this evening? a) 1/3 b) 5/3 c) 3/5 d) 3/1 c) 3/5 There is an 80 percent chance Georgina will wear her jean jacket. There is a 60 percent chance it won't rain. What are the chances that Georgina's jacket gets wet? a) 48% b) 140% c) 32% d) 80% c) 32% This is an intersection between it raining and Georgina wearing her jean jacket. This means multiplying the likelihoods of both events. P(rain∩jacket) =P(rain)×P(jacket)=0.40×0.80=0.32 In the next hour, there is a 25 percent chance that Bruce will put on a suit. Also in the next hour, there is a 60 percent chance that Clark will take off his glasses. There is a 9 percent chance that both of these events might happen. What is the likelihood that either Clark will take off his glasses or Bruce will put on a suit? a) 76% b) 24% c) 15% d) 94% a) 76% This is a union between Bruce putting on a suit and Clark taking off his glasses. P(suit ∪no glasses)= P(suit)+P(no glasses)−P(suit ∩no glasses) =0.25+0.60−0.09 =0.76=76% A misuse of assumptions occurs when someone tests something that is accepted to be true but has not yet been proven. T/F F. A misuse of an assumption occurs when it is used to make conclusions. Oscar surveys thirty households in Ohio about their preferences for pasta and, based on the results, concludes that a majority of Midwesterners prefer spaghetti over egg noodles. He is correct in making this inference. T/F