The time for this z-score is 3.28.
The formula for z-scores is
z = (X-μ)/σ
Using our information, we have
-1.2 = (X-4.6)/1.1
Multiply both sides by 1.1:
-1.2(1.1) = X - 4.6
-1.32 = X - 4.6
Add 4.6 to both sides:
-1.32 + 4.6 = X - 4.6 + 4.6
3.28 = X
It is not 7 it is 12. 3x4 = 12
Yolanda will sew 54 buttons in 3 days.
If she sews 3 sweaters a day then, by the end of each day she will have 18. After three days she will have 54.
hope this helps and have an awesome day !
