Question1 1 points Save Answ Provide an appropriate response. A new phone system
ID: 3309643 • Letter: Q
Question
Question1 1 points Save Answ Provide an appropriate response. A new phone system was installed last year to help reduce the expense of personal calls that were being made by employees. Before the new system was installed, the amount being spent on personal calls follows a normal distribution with an average of $800 per month and a standard deviation of $50 per month. Refer to such expenses as PCE's (personal call expenses). Find the probability that a randomly selected month had a PCE that falls below $650. 0.0013 0.9987 0 0.81 25 0.1875 Moving to another question will save this response. Question 1 of 3Explanation / Answer
Ans:
1)Mean=800
standard deviation=50
z=(650-800)/50=-150/50=-3
P(z<-3)=0.0013
2)Mean=60000
standard deviation=1400
z=(58600-60000)/1400=-1
P(z>-1)=0.8413
3)Mean=12.18
standard deviation=0.04
z(12.08)=(12.08-12.18)/0.04=-2.5
z(12.14)=(12.14-12.18)/0.04=-1
P(-2.5<=z<=-1)=P(z<=-1)-P(z<=-2.5)
=0.1587-0.0062=0.1525