Question

QUESTION 13

1. Based on the definition of significance described in this Quiz, is Easton's weight 'significantly low'?

   A.

   Yes

   B.

   No

   QUESTION 14

   Now we turn our attention to a new word problem. The numbers are bigger, but the ideas are the same!

   Suppose teachers in a certain state earn an annual salary of $54,600, on average. The standard deviation is $10,200. The salaries are normally distributed.

   95% of teachers earn within what range of money for their annual salary?

   A.

   Between $44,400 and $64,800

   B.

   Between $34,200 and $75,000

   C.

   Between $24,000 and $85,200

   QUESTION 15

   Suppose teachers in a certain state earn an annual salary of $54,600, on average. The standard deviation is $10,200. The salaries are normally distributed. Mrs. Smith is a teacher who has an annual salary of $60,000. What kind of z-score will Mrs. Smith have?

   	A.	Negative
   	B.	Zero
   	C.	Positive

Answer 1

Here's answer to all questions, please let me know in case you've doubts.

Can't answer Q13, as there is a pre-text to this question, which is not in the question.

14. We have been given a normal distribution parameters as :

Mean = $54,600

Stdev = $10,200

95% CI is basically with a Z -score of 1.96 and the formula to take out the 95% CI is :

Mean +/ - Z*Stdev

= 54600 +/- 2*10200

= $34,200 to $75,000

Answer is B

15.

The Z-score of a teacher with $60,000 salary is ?

Z = (X-mean)/Stdev

Z = (60000-54600)/10200 = 0.52941

The Z-score is +.52941, which is a positive score.

C is correct