Step-by-step explanation:
a. First, find the z-score.
z = (x − μ) / σ
z = (80 − 74.0) / 12.5
z = 0.48
Use a calculator or table to find the probability.
P(z < 0.48) = 0.6844
b. Find the standard deviation of the sample.
σₓ = σ / √n
σₓ = 12.5 / √4
σₓ = 6.25
Find the z-score.
z = (x − μ) / σ
z = (80 − 74.0) / 6.25
z = 0.96
Use a calculator or table to find the probability.
P(z < 0.96) = 0.8315
c. When the distribution of the population is normal, then the distribution of the sample mean is also normal.
Answer:
yes it square root is irational
The number of 10 chips stacks that Dave can make if two stacks are not considered distinct is 110.
The solution
To get the symmetric stacks, one has to subtract the symmetric stacks to know the ones that are asymmetric.
The symmetric are flipped. Given that they are double counted what we have to do is to divide through by 2.
6/2 = 3
10/2 = 5
4/2 = 2
1/2(10C6) - (5C3) + (5C3)
0.5(210-10+10)
= 110
