Q2 Data-Driven Decision Making

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?

• 4.3 to 7.3

• 2.8 to 8.8

• 1.3 to 13.0

• 3.8 to 7.5

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?

• Z-score

• Mode

• Median

• 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?

• Scatterplot

• Pie Chart

• Histogram

• Box Plot

Given the following data set: 60, 41, 30, 15, 34, 30 What is the Median?

• 32

• 30

• 34

• 35

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? (Pick 2)

• The test statistic is less than the critical value

• The null hypothesis is rejected given a probability of being wrong

• The test statistic is greater than the critical value

• The null hypothesis is accepted given a probability of being correct.

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?

• T-statistic

• Z-score

• Median

• R-squared

What does it mean when an individual data point has a z-score of +1?

• The data point is one standard deviation less than the mean of the data set.

• The sample standard deviation of the data set is negative.

• The data point is less than the mean of the data set.

• 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:

• Histogram

• Bar chart

• Scatterplot

• Pareto chart

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)?

• How many days are considered?

• Is there a causal relationship between sales and site visits?

• Can we compare sales in dollars to number of visits?

• Is the central limit theorem applicable?

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?

• 68%

• 95%

• 99.7%

• 100%