(1 point) Because of the relatively high interest rates, most consumers attempt
ID: 2946746 • Letter: #
Question
(1 point)
Because of the relatively high interest rates, most consumers attempt to pay off their credit card bills promptly. However, this is not always possible. An analysis of the amount of interest paid monthly by a bank's Visa cardholders reveals that the amount is normally distributed with a mean of 28 dollars and a standard deviation of 9 dollars.
A. What proportion of the bank's Visa cardholders pay more than 30 dollars in interest?
Proportion =
B. What proportion of the bank's Visa cardholders pay more than 37 dollars in interest?
Proportion =
C. What proportion of the bank's Visa cardholders pay less than 19 dollars in interest?
Proportion =
D. What interest payment is exceeded by only 21% of the bank's Visa cardholders?
Interest Payment =
Explanation / Answer
Sol:
mean=28
sd=9
SolutionA:
P(X>30)
z=x-mean/sd
=30-28/9
=2/9
=0.222
P(Z>0.222)
=1-P(Z<0.222)
=1-0.5871
=0.4129
ANSWER:0.4129
Solutionb:
P(X>37)
z=x-mean/sd
=37-28/9
=1
P(Z>1)
=1-P(Z<1)
From standard normal tables
=1-0.8413
=0.1587
ANSWER:0.1587
Solutionc:
P(X<19)
Z=x-mean/sd=19-28/9
z=-1
P(Z<-1)
=1-P(Z<1)
=1-P(Z<1)
=1-0.8413
=0.1587
ANSWER:0.1587
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.