* Example for instructions x is a Normally distributed random variable….. Mean = 100 Std dev...



Example for instructions

x is a Normally distributed random variable…..
Mean =	100
Std dev =	25

a. What is the probability of a value of x that is more than 140?

Z =	1.60	=(140-B6)/B7
Table prob = .4452
	p(x>140) = .5-.4452 =		0.0548

The probability of a value of x that is more than 140 is 0.0548

*****Complete #3 two ways*********

i. Same as in Example above

ii. using the Excel NORMDIST and NORMINV functions

demonstrated in the Prob Dist podcast

NOTE: Excel functions (just as the table) may not directly give the answer you are looking for, you must understand what they return and how to use it.

3. The average amount parents spent per child on back-to-school clothes in Fall 2019 was $635. Assume the standard deviation is $150 and the amount spent is normally distributed.

a. What is the probability that the amount spent on a randomly selected child is more than $800?

b. What is the probability that the amount spent on a randomly selected child is more than $500

c. 95% of the parents will spend more than what amount?

Solutions

Expert Solution

milcah answered 2 days ago

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