Question 1

The forming of groups into internally homogeneous groups where each has a unique characteristic, different from other groups, is called cluster analysis.

Accepted Answer

A) True 
 B)False

Question 2

Carmen pulled transactions from the month of March to see if there is an association between coffee and breakfast sandwich purchases. After running through confidence and expected confidence calculations, she calculated the lift ratio at 1.52. What association does a calculated lift ratio of 1.52 reflect?

Accepted Answer

A)  A lift ratio of 1.52 is over 1, indicating a weak association between coffee and breakfast sandwiches. 
B)  1.52 implies that identifying a person who purchases coffee and a breakfast sandwich is 52% better than guessing that a random person will purchase a breakfast sandwich. 
C)  1.52 implies that 52% of consumers will purchase coffee and not a breakfast sandwich. 
D)  The lift ratio cannot determine the association between purchases.

Question 3

Which method uses the farthest distance between a pair of observations that do not belong to the same cluster?

Accepted Answer

A)  The single linkage method 
B)  The complete linkage method 
C)  The centroid method 
D)  The average linkage method

Question 4

In understanding the association rules, it is best to think of them as an If-Then statement.

Accepted Answer

A) True 
 B)False

Question 5

The marketing department is examining the data pulled from the retail stores over the month of December. In this time period, three items are of interest, Sound Bars, LED under counter lights, and shelving units. 
-In researching if two of the items are purchased, if the third will be also, the following confidence level was calculated at 0.575, with an expected confidence of 0.10. Calculate the lift ratio.

Accepted Answer

A)  0.0575 
B)  5.75 
C)  0.6389 
D)  0.475

Question 6

When evaluating large data sets, it is customary to cluster large data sets using the k-means to reduce the computation of measures during each iteration compared to hierarchical clustering methods.

Accepted Answer

A) True 
 B)False

Question 7

Martin wants to understand the strength of association among toilet paper, milk, and eggs. Of 5,000 transactions, the number of transactions including antecedent is 1,520 whereas the number of transactions including both antecedent and consequent transactions is 690. Calculate the confidence.

Accepted Answer

A)  0.4420 
B)  0.3040 
C)  0.4539 
D)  0.1380

Question 8

In cluster analysis, measures are used to form clusters. However, when large data sets are imported into R, sometimes the variables do not share the same format. To overcome this, you standardize the data using the _____ function.

Accepted Answer

A)  score 
B)  scale 
C)  standard 
D)  dist

Question 9

The use of error sum of squares to measure the loss of information that occurs when observations are clustered describes which method?

Accepted Answer

A)  The centroid method 
B)  The complete linkage method 
C)  The average linkage method 
D)  Ward's method

Question 10

Eva is trying to figure out the total number of possible combinations for 130 inventory items. Calculate the number for Eva.

Accepted Answer

A)  3.80887E + 61 possible combinations 
B)  1.126E + 124 possible combinations 
C)  1.06112E + 62 possible combinations 
D)  1.26780E + 251 possible combinations

Question 11

Use the proportion of the following transactions that contain both Latte and Scone and calculate the Support of the association rule.

Accepted Answer

A)  0.25 
B)  0.70 
C)  0.30 
D)  0.75

Question 12

Based on the following table, what is the proportion of the transactions that include both milk and bread?

Accepted Answer

A)  0.80 
B)  0.60 
C)  0.20 
D)  0.40

Question 13

Using R, what function is used to view the rules by their lift ratios?

Accepted Answer

A)  lookup 
B)  apriori 
C)  rules 
D)  sort

Question 14

When using R for Agglomerative Clustering, the plot function is used to create the dendrogram as well as a banner plot. What function is used to split these results into distinct clusters?

Accepted Answer

A)  aResult 
B)  data.frame 
C)  cutree 
D)  view

Question 15

Of 8,000 grocery store transactions, 795 have been identified as having coffee, ice cream, and chips as part of the same transaction. Calculate the support of the association rule.

Accepted Answer

A)  10.063 
B)  0.0994 
C)  7.95 
D)  0.795

Question 16

Martin wants to understand the strength of association among toilet paper, milk, and eggs. Of 8,000 transactions, the number of transactions including antecedent is 1,710 whereas the number of transactions including both antecedent and consequent transactions is 750. Calculate the confidence.

Accepted Answer

A)  0.3075 
B)  0.2138 
C)  0.4386 
D)  0.0938

Question 17

k-means clustering algorithm can be summarized as all of the following except for

Accepted Answer

A)  Can be either numerical or character variables. 
B)  Specify the k value. 
C)  Randomly assign k observations as cluster centers. 
D)  Assign each observation to its nearest cluster center.

Question 18

In reviewing purchases at Costco on a given Saturday, 645 transactions out of 1,250 included toilet paper, detergent, and clothing or {toilet paper, detergent} => {clothing}. Calculate the support of the association rule.

Accepted Answer

A)  0.516 
B)  1.516 
C)  1,250 
D)  6.45

Question 19

When using R, after the data is imported, set.seed function is used to set the random seed and the k function sets the k parameters to preselect the number of clusters.

Accepted Answer

A) True 
 B)False

Question 20

Of the following options, which is not accurate for clustering?

Accepted Answer

A)  Euclidean distance or Manhattan distance measures for numerical variables and matching. 
B)  AGNES takes each observation in the data initially and forms its own cluster. 
C)  Hierarchical clustering commonly follows agglomerative and divisive clustering. 
D)  Cluster analysis is where small amounts of data are organized against larger statistical sets.

Exam 11: Unsupervised Data Mining

The forming of groups into internally homogeneous groups where each has a unique characteristic, different from other groups, is called cluster analysis.

Which method uses the farthest distance between a pair of observations that do not belong to the same cluster?

In understanding the association rules, it is best to think of them as an If-Then statement.

When evaluating large data sets, it is customary to cluster large data sets using the k-means to reduce the computation of measures during each iteration compared to hierarchical clustering methods.

Martin wants to understand the strength of association among toilet paper, milk, and eggs. Of 5,000 transactions, the number of transactions including antecedent is 1,520 whereas the number of transactions including both antecedent and consequent transactions is 690. Calculate the confidence.

In cluster analysis, measures are used to form clusters. However, when large data sets are imported into R, sometimes the variables do not share the same format. To overcome this, you standardize the data using the _____ function.

The use of error sum of squares to measure the loss of information that occurs when observations are clustered describes which method?

Eva is trying to figure out the total number of possible combinations for 130 inventory items. Calculate the number for Eva.

Use the proportion of the following transactions that contain both Latte and Scone and calculate the Support of the association rule.

Based on the following table, what is the proportion of the transactions that include both milk and bread?

Using R, what function is used to view the rules by their lift ratios?

When using R for Agglomerative Clustering, the plot function is used to create the dendrogram as well as a banner plot. What function is used to split these results into distinct clusters?

Of 8,000 grocery store transactions, 795 have been identified as having coffee, ice cream, and chips as part of the same transaction. Calculate the support of the association rule.

Martin wants to understand the strength of association among toilet paper, milk, and eggs. Of 8,000 transactions, the number of transactions including antecedent is 1,710 whereas the number of transactions including both antecedent and consequent transactions is 750. Calculate the confidence.

k-means clustering algorithm can be summarized as all of the following except for

In reviewing purchases at Costco on a given Saturday, 645 transactions out of 1,250 included toilet paper, detergent, and clothing or {toilet paper, detergent} => {clothing}. Calculate the support of the association rule.

When using R, after the data is imported, set.seed function is used to set the random seed and the k function sets the k parameters to preselect the number of clusters.

Of the following options, which is not accurate for clustering?