As described in z-distribution the answers are given below:
a) The 95% confidence interval estimate for the population mean spending by a customer on visiting salon per month is given as follows: (747, 853).
b) The sampling error at 95% confidence level is of: $35.78.
What is a z-distribution ?
The normal distribution with a mean of 0 and a standard deviation of 1 is referred to as the standard normal distribution (also known as the Z distribution) (the green curves in the plots to the right). It is frequently referred to as the bell curve since the probability density graph resembles a bell.
solution:
The bounds of the confidence interval are given as follows:
In which:
is the sample mean.
z is the critical value.
n is the sample size. is the standard deviation for the population.
The parameters for this problem are given as follows:
Hence the lower bound of the interval is of:
800 - 200 x 1.96/square root of 55 = 747.
The upper bound of the interval is of:
800 + 200 x 1.96/square root of 55 = 853.
The sampling error for a sample size of 120 is calculated as follows:
200 x 1.96/square root of 120 = $35.78.
To learn more about the z-distribution from the given link
brainly.com/question/4079902
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Answer:
width=60 length=540
Step-by-step explanation:
(w+9w)*2=1200
Answer:
C
Step-by-step explanation:
NEGATIVE TIMES POSITIVE WILL GIVE A NEGATIVE PRODUCT
55/9 = 6.11
57/7 = 8.14
41/5 = 8.2
65/8 = 8.125
The answer is 41/5 is larger than 8.15
Standard deviation = √(n * p * q)
You are given n and p
q = 1 - p
q = 1 -0.2 = 0.8
Standard deviation = √(21 * 0.2 * 0.8)
=√3.36 = 1.83
The answer is A.
