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.
Answer: 4
Step-by-step explanation:
Amount of chocolate chips = 6 1/2
Amount of cups of flour = 5/2
The cups of flour should be changes to a mixed fraction and this will be 5/2 = 2 1/2
The question simply means we should find the difference between the fractions given and this will be:
= 6 1/2 - 2 1/2
= 4
I dont know if its 100% correct but I believe its this one
Answer:
d
Step-by-step explanation:
30% of the 30 marbles is nine and 9-30 = 21 so your answer is 21