A caterer records...

Question

A caterer records the number of weddings he works during 5 weeks of the summer: {0,3,4,3,6}. If he caters 3 weddings the next week, in what ways do the mean and the standard deviation of the data set change?
 
A) the mean increases, the standard deviation increases
B) The mean increases, the standard deviation decreases
C) the mean decreases, the standard deviation increases
D) the mean decreases, the standard deviation decreases

Answer 1

mean{0,3,4,3,6}=3.2000

mean{0,3,4,3,6,3}=3.1667

decrease

 

standard deviation{0,3,4,3,6}=2.1679

standard deviation{0,3,4,3,6,3}=1.9408

decrease

 

answer -> D

 

note: i agree with final answer posted by Carlos

Answer 2

Actual mean > 3

Next week, weddings = 3, then:

New mean < Actual mean.

 

Actual STD ~ 1.2.

Next week, STD ~ 0.2, then:

New STD < Actual STD.

 

Correct --> D)