Question 1167659: According to research, the mean cost of safety equipement per year for colleges in Canada is $15,000.00. Suppose that these costs are normally distributed with a standard deviation of $5,000.00. If a Canadian College is selected at random, find the following probabilities.
For parts (a), (b), (c) express your answers as probabilities in decimal form (i.e. 0.0003 instead of 0.0300%), and round your answers to 4 decimal places.
(a) The cost is less than $12,650.00.
(b) The cost is above $16,400.00.
(c) The cost is between $12,650.00 to $16,400.00.
For part (d), round your answer to 2 decimal places.
(d) What amount of cost is the cut-off for the top 10.20% of Canadian Colleges?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
a. z < (12650-15000)/5000 or < -0.47
probability is 0.3192
b. is z>0.28 or probability 0.3897
c. is the probability remaining or 0.2911.
The top 10.20% for Canadian colleges is from the table a z-value of 1.27. Using the calculator value and rounding only here to show but rounding only at the end.
1.2702=(x-15000)/5000
6351.19=x-15000
x=$21351.19 as the 10.20%ile to two decimal places.
|
|
|
