WGU C207 Data-Driven Decision Making Final Pre-Assessment (2023) Questions And Answers

WGU C207 DATA-DRIVEN DECISION MAKING FINAL An online retailer selling workout apparel has a large increase in sales during December and declares that their weekly newspaper ad resulted in higher sales. What misuse of statistics may the retailer have used in making this decision? (correct answers)Association and Causation An educator collects eighth grade math scores from a local school and used this data to recommend curriculum changes for grades 8 - 12. What misuse of statistics may the educator have used in making this recommendation? (correct answers)Not a representative sample An economist wishes to study the distribution of household income in a Midwestern city. He randomly selects a sample from 12 households. He notices two large incomes in his sample. Which measure best represents the middle of the incomes? (correct answers)Median A cable company offers its customers both cable television and internet. What statistical rule should be used to determine the probability that customers will have both cable television and internet? (correct answers)Multiplication A department store is considering a new credit policy to reduce defaults on payments. Its records show that 95% of defaults have at least 2 late payments. Also, 3% of all customers default and 30% of those customers who have not defaulted have a least 2 late payments. What statistical rule should be used to find the probability that a customer will default given that at least 2 payments were late? (correct answers)Bayes Theorem Based on quality checks at plastic bags manufacturer, the breaking strength of their bags has a mean of 50.5 and a standard deviation of 1.6. A customer's test of the bags finds bag strength of 54.2 or less. Which statistical measure should be used to help determine the probability of the customer's test occurring? (correct answers)z-score The mean of 100 bank customers' waiting times for teller service is 5.8 minutes with a standard deviation of 1.5. What time range would represent a 95.4% probability customer waiting time? (correct answers)2.8 to 8.8 The revenue of NBA teams ranges from $226 million for the New York Knicks to $92 million for the Milwaukee Bucks. Which statistic would measure how far each team's revenue is from the NBA revenue mean? (correct answers)Variance A local plumbing company is analyzing to see how the number weeks taken for their payment receipts is distributed. Which graphical analysis technique should they use? (correct answers)Histogram Given the following data set:60, 41, 30, 15, 34, 30 What is the Median? (correct answers)32 A loan officer compares the interest rates for 48 month fixed-rate loans and 48 month variable-rate auto loans. Two independent, random samples of auto loans are selected. Which two results happen when the null hypothesis is rejected using a t-test? (correct answers)The null hypothesis is rejected given a probability of being wrong The test statistic is greater than the critical value An online marketing organization designed a social media that wants to earn at least $250,000 in revenue. The campaign will reach 10,000 viewers and receive orders with a mean of $50 and standard deviation $10. Which measure should be used to determine the probability of the campaign receiving at least $250,000? (correct answers)Z-score What does it mean when an individual data point has a z-score of +1? (correct answers)The data point is one standard deviation greater than the mean of the data set. A descriptive graph depicting whether there is a correlation or relationship between two variables, such as car mileage and resale price would be: (correct answers)Scatterplot A food chain finds that there is a strong positive correlation between average daily sales for their pizza store and the number of daily visits to their website. What should be considered before the pizza chain can conclude that the daily sales are driving the number of visits to their website (or vice versa)? (correct answers)Is there a causal relationship between sales and site visits? We examine a population with normal distribution having mean of 1000 and standard deviation 50. What percentage of the population lies between 850 and 1150? (correct answers)99.7% We examine a population with normal distribution having mean 1000 and standard deviation 50. What percentage of the population lies between 900 and 1100? (correct answers)95% How are z-scores from a population with normal distribution distributed? (correct answers)Normal Distribution with mean 0 standard deviation 1 What z-score should be used to find the 99% confidence interval? (correct answers)2.575 A stock broker offers two portfolios for his clients. There are various risks with each portfolio and his is trying to minimize the risk of loss. Both portfolios have the same mean return.Which measure should the employee use to decide between these alternatives? (correct answers)Variance A comparison between the effectiveness of online vs. newspaper coupons was conducted over a 3 month period to see which method brought in greater average revenue per customer.Which statistic should the pizza manager recommend use to determine promotional method to use? (correct