Now that we've been open for 15 weeks, we want to compare the average weekly sales on
Saturday to the average weekly sales on Sunday. Which is the appropriate statistical test? -
ANSWER t-test
We perform a t-test and our p-value is less than 0.05. Should we reject the null? - AN-
SWER Yes. We have a significant difference between the groups.
Which statistical test can we use to test a correlation between customers per day and sales
per day? - ANSWER Linear Regression
Which R-square gives us a better indication there is a relationship between customers per
day and sales per day? - ANSWER 0.75
Our regression model is y = 50 + 10X. y is the sales per day and x is the number of customers
per day. What will our sales be if we have 20 customers? - ANSWER $250
As we continue to measure the sales per day and the customers per day, they consistently
increase together and decrease together. What is this an example of? - ANSWER Homo-
scedasticity
We would like to examine what our customers that buy donuts in the afternoon have in
common. Which analysis technique applies? - ANSWER Cluster
In addition to customers per day, we are also going to use temperature to predict our sales
per day. Which analysis technique applies? - ANSWER Multiple Regression
1
, We wish to compare the average sales on Monday, Wednesday and Friday. Which analysis
technique applies? - ANSWER ANOVA
When we use number of customers per day to predict sales, which variable is the number of
customers? - ANSWER Independent
Our p-value is .042 when we perform the regression analysis to determine if number of cus-
tomers can predict sales per day. Are number of customers a significant predictor? - AN-
SWER Yes
We want to use the age of the customer to predict if they order creamer in their coffee.
Which analysis technique applies? - ANSWER Logistic regression
We notice a repeating pattern in the sale of one of our products. What time series pattern is
this? - ANSWER Cyclical
We see a peak in our sales each July. What time series pattern is this? - ANSWER Sea-
sonal
We notice a strong increase month to month over the past 18 months in our sales? What
time series pattern is this? - ANSWER Trend
We opened our donut shop last year. Our average sales per day are $2000 with a standard
deviation of $50. What is the probability of our sales being between $2050 and $1950 on a
randomly selected day? - ANSWER 68.2%
Tony is our newest employee. We want to compare Tony's average sales to the average of all
of our employees' sales. Which is the appropriate method? - ANSWER z-score
2
Saturday to the average weekly sales on Sunday. Which is the appropriate statistical test? -
ANSWER t-test
We perform a t-test and our p-value is less than 0.05. Should we reject the null? - AN-
SWER Yes. We have a significant difference between the groups.
Which statistical test can we use to test a correlation between customers per day and sales
per day? - ANSWER Linear Regression
Which R-square gives us a better indication there is a relationship between customers per
day and sales per day? - ANSWER 0.75
Our regression model is y = 50 + 10X. y is the sales per day and x is the number of customers
per day. What will our sales be if we have 20 customers? - ANSWER $250
As we continue to measure the sales per day and the customers per day, they consistently
increase together and decrease together. What is this an example of? - ANSWER Homo-
scedasticity
We would like to examine what our customers that buy donuts in the afternoon have in
common. Which analysis technique applies? - ANSWER Cluster
In addition to customers per day, we are also going to use temperature to predict our sales
per day. Which analysis technique applies? - ANSWER Multiple Regression
1
, We wish to compare the average sales on Monday, Wednesday and Friday. Which analysis
technique applies? - ANSWER ANOVA
When we use number of customers per day to predict sales, which variable is the number of
customers? - ANSWER Independent
Our p-value is .042 when we perform the regression analysis to determine if number of cus-
tomers can predict sales per day. Are number of customers a significant predictor? - AN-
SWER Yes
We want to use the age of the customer to predict if they order creamer in their coffee.
Which analysis technique applies? - ANSWER Logistic regression
We notice a repeating pattern in the sale of one of our products. What time series pattern is
this? - ANSWER Cyclical
We see a peak in our sales each July. What time series pattern is this? - ANSWER Sea-
sonal
We notice a strong increase month to month over the past 18 months in our sales? What
time series pattern is this? - ANSWER Trend
We opened our donut shop last year. Our average sales per day are $2000 with a standard
deviation of $50. What is the probability of our sales being between $2050 and $1950 on a
randomly selected day? - ANSWER 68.2%
Tony is our newest employee. We want to compare Tony's average sales to the average of all
of our employees' sales. Which is the appropriate method? - ANSWER z-score
2
