Answer:
30%
Step-by-step explanation:
Initial area is 40 square feet
Final area is 28 square feet
Difference between the initial and final areas will be 40-28=12 square feet
Taking the initial area as the base area and expressing the area change in percentage then the percentage decrease will be equivalent to

Therefore, the decrease in area expressed as a percentage is equal to 30%
Use Pie the method we all learned i really can’t remember but i think it’s 3.14
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:
-6 and 2
Step-by-step explanation:
See attached worksheet.