Answer:
0.13% of customers spend more than 46 minutes
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What percentage of customers spend more than 46 minutes?
This is 1 subtracted by the pvalue of Z when X = 46. So



has a pvalue of 0.9987
1 - 0.9987 = 0.0013
0.13% of customers spend more than 46 minutes
Answer:
1%
Step-by-step explanation:
We need our two numbers to have the same units. Since one number is in cents and the other is in dollars, we should change one of them. It could be either one.
Both numbers in cents:
50/4000
OR, both numbers in dollars:
.50/40.00
Either of these will work. Divide, you will get a decimal answer. Then multiply by 100 to change to a percent.
50÷4000 (OR .5/40)
= 0.0125
times by 100
0.0125 × 100
= 1.25% but the directions said to round to the nearest whole number, that's 1%
Answer:
B & D
Step-by-step explanation:
B & D
Answer:
4180 to 5230$
Step-by-step explanation:
1. Lets find the expenses she has to make -> 4*90+660=1020$(4 new tires + other expenses)
2. As her income is not set strictly we can guess the range she can save(More accurate calculations depends on her strict incomes). We have 5200-1020=4180$(if she gets paid 5200$) and 6250-1020= 5230$(if she gets paid 6250$).
3. So the range of savings vary from 4180 to 5230$$.