The error rate has decreased after changing the painting process.
<u>Step-by-step explanation:</u>
Abdulla knows that 20 percent of the parts have an error in their painting. After suggesting changes in painting process, he wants to know whether the error rate has changed.
Number of parts in the random sample=400400400
Number of parts that had an error=606060
We have to determine what percentage of 400400400 is 606060
After changing the painting process 0.15% of parts have error.
The previous percentage was 20.Hence the error rate has clearly changed.
Answer:27 pieces were sold at the original price.
63 pieces were sold at the new price
Step-by-step explanation:
Let x represent the number of pieces of pottery that was sold at the original price.
Let y represent the number of pieces of pottery that was sold at the new price.
They sold some of their pottery at the original price of $9.50 for each piece. This means that the amount that they got from selling x pieces of pottery at the original price would be 9.5x
They later decreased the price of each piece by $2. This means that the new price was 9.5 - 2 = $7.5
This means that the amount that they got from selling x pieces of pottery at the new price would be 7.5y
If they sold all 90 pieces and took in $729, then the equations are
x + y = 90
9.5x + 7.5y = 729 - - - - - - - - - -1
Substituting x = 90 - y into equation 1, it becomes
9.5(90 - y) + 7.5y = 729
855 - 9.5y + 7.5y = 729
- 9.5y + 7.5y = 729 - 855
- 2y = - 126
y = - 126/- 2 = 63
Substituting y = 63 into x = 90 - y, it becomes
x = 90 - 63 = 27
No. of layers= 2^7 = 128 layers
thickness = 128*0.1 = 12.8mm
hope it helps.
