To solve this problem, we use the formula:
z = (x – u) / s
where z is the z score value which can be obtained from
the tables, x is the sample value, u is the mean = 6.3 min, and s is the std
dev = 2.2 min
at P value = 0.90, the z = 1.28, finding for x:
x = z s + u
x = 1.28 * 2.2 + 6.3
x = 9.116
at P value = 1.0, the z = 3.49, finding for x:
x = z s + u
x = 3.49 * 2.2 + 6.3
x = 13.978 ~ 14
Therefore the longest 10% calls last about 9.1 minutes to
14 minutes
Consider,
. Let's say
then the problem reduces to
. (Do you understand this step?)
So then replacing a again with our definition we get,
.
Answer:
All of the Above.
Step-by-step explanation:
Monthly Payments is similar to length of time. Interest rate is the amount you pay back on a monthly scale.
Answer:
8
Step-by-step explanation:
45.5 + 15.5x < 175
15.5x < 129.5
x < 8.35
Answer: 8
