A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is σ = 15. a. Compute the 95% confidence interval for the population mean. b. Assume that the same sample mean was obtained from a sample of 120 times. Provide a 95% confidence interval for the population mean. c. What is the effect of a larger sample size on the interval estimate?

a) (76.21,83.79)

b) (77.32,82.68)    

c) Interval decreases    

Step-by-step explanation:

We are given the following information in the question:

Sample size, n = 60

Sample mean = 80

Sample standard Deviation, s = 15

a) 95% Confidence interval:

Putting the values, we get,

b) Sample size, n = 120

95% Confidence interval:

c) As observed increasing the sample size, the confidence interval become smaller.

or

"image"

step-by-step explanation:

in most of these problems, the notation is that the point with a "prime" is the image of the point without. that is, b' is the image of b.

here, there is no dilation or reflection. there is simply translation (with no direction shown). which figure you call the "preimage" and which one you call the "image" is up to you. as a matter of convention, the naming is as described above.