Find the z-score for the value 88, when the mean is 70 and the ...

[Haya94]

Find the z-score for the value 88, when the mean is 70 and the standard deviation is 1.
 
  A) z = 17.00 B) z = -1.24 C) z = 1.24 D) z = 18.00

Question 2

A recent survey was conducted to compare the cost of solar energy to the cost of gas or
  electric energy.
 
  Results of the survey revealed that the distribution of the amount of the
  monthly utility bill of a 3-bedroom house using gas or electric energy had a mean of
  124.00 and a standard deviation of 15.00. Assuming the distribution is
  mound-shaped and symmetric, would you expect to see a 3-bedroom house using gas
  or electric energy with a monthly utility bill of 236.50 ? Explain.

[Tabitha_2016]

Answer to Question 1

D

Answer to Question 2

The z-score for the value 236.50 is:
z =
x - x
s
=
236.5 - 124
15
= 7.5
An observation that falls 7.5 standard deviations above the mean is very unlikely. We would not expect to see a
monthly utility bill of 236.50 for this home.

[Haya94]

Thanks for the timely response, appreciate it

[31809pancho]

Excellent