Answer:
94
Step-by-step explanation:
Margin of error = E = $ 120
Confidence Level = 95%
The z-score for 95% confidence level from the z-table = z = 1.96
Population standard deviation = σ = $593
Sample size = n = ?
The formula to calculate the margin of error is:
Re-arranging the equation, we get:
Using the given values in above equation, we get:
Rounding of to next higher integer, we get n = 94
Thus, we need a sample size of 94 to estimate an unknown population mean μ
So first you combine all the equations and make them add up to 56.
The equation should look as such: 2y + 8 = 56
Then we solve for y
Work: 2y + 8 = 56
2y = 48
y = 24
I hope this helps!
Answer:
Two
Step-by-step explanation:
If you have one and added one you have two
Answer:
Step by step explanation:
Answer:
0.04865 or 4.9%
Step-by-step explanation:
This is a binomial distribution function which is expressed as:
Where:
- p=probability of success
- x=number of successful events
- n=size of the sample
Given that p=0.03, n=12 and x=2+, the probability of a cash back is calculated as:
![P(X=x){n\choose x}p^x(1-p)^{n-x}\\\\P(X\geq 2)=1-P(X\leq 1)\\\\=1-[{12\choose 0}0.03^0(0.97)^{12}+{12\choose 1}0.03^1(0.97)^{11}]\\\\\\=1-[0.69384+0.25751]\\\\\\=0.04865](https://tex.z-dn.net/?f=P%28X%3Dx%29%7Bn%5Cchoose%20x%7Dp%5Ex%281-p%29%5E%7Bn-x%7D%5C%5C%5C%5CP%28X%5Cgeq%202%29%3D1-P%28X%5Cleq%201%29%5C%5C%5C%5C%3D1-%5B%7B12%5Cchoose%200%7D0.03%5E0%280.97%29%5E%7B12%7D%2B%7B12%5Cchoose%201%7D0.03%5E1%280.97%29%5E%7B11%7D%5D%5C%5C%5C%5C%5C%5C%3D1-%5B0.69384%2B0.25751%5D%5C%5C%5C%5C%5C%5C%3D0.04865)
Hence, the probability of a cash return is 0.04865 or 4.9%
