The given operation involves just swapping the two rows, so carrying out

on the matrix gives
Answer:
The standard deviation of number of hours worked per week for these workers is 3.91.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

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. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.
In this problem we have that:
The average number of hours worked per week is 43.4, so
.
Suppose 12% of these workers work more than 48 hours. Based on this percentage, what is the standard deviation of number of hours worked per week for these workers.
This means that the Z score of
has a pvalue of 0.88. This is Z between 1.17 and 1.18. So we use
.





The standard deviation of number of hours worked per week for these workers is 3.91.
Answer:
603 miles in 3 days
Step-by-step explanation:
Let's find out how many miles in 1 day:
- 1,005 ÷ 5 = 201
- So, Sarah drives 201 miles in 1 day
Let's find out how many miles in 3 days:
- 3 days = 1 day × 3
- 3 days = 201 × 3
- 3 days = 603 miles
I hope this helps!