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.
9514 1404 393
Answer:
-13 < x ≤ 4
Step-by-step explanation:
The round bracket means the lower limit is not included in the interval. The square bracket means the upper limit is included.
-13 < x ≤ 4
3/2
I picked a point and counted up 3 and over 2 to the next point
Answer:
y=1/4x+6 1/4
Step-by-step explanation: