Answer:
0.0039 is the probability that the sample mean hardness for a random sample of 12 pins is at least 51.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 50
Standard Deviation, σ = 1.3
Sample size, n = 12
We are given that the distribution of hardness of pins is a bell shaped distribution that is a normal distribution.
Formula:
Standard error due to sampling =

P(sample mean hardness for a random sample of 12 pins is at least 51)
Calculation the value from standard normal z table, we have,
0.0039 is the probability that the sample mean hardness for a random sample of 12 pins is at least 51.
I am not sure maybe it is 6
Part 1:
6(x-5) = 5(x+5) (x = 55)
4y + 2 (-3 + 2y) = 1-y (x = 7/9)
Part 2:
4(a-6) = 8a - (4a-24) (No Solution)
4(2x-8) = 8(x-8) (No Solution)
2(3x-3) = -6x-6 (Identity (x = 0))
You would subtract the tax first which 62.99-2.99=60$. Then you would divide the $60 left by 6 and 60 divided by 6 equals 10 so each shirt costs $10.