"Refer to the accompanying data display that results from a sample of airport data speeds in Mbps. Complete parts (a) through (c) below. TInterval (13.046,22.15) x= 17.598 Sx = 16.01712719 n= 50 a. Express the confidence interval in the format that uses the ""less than"" symbol. Given that the original listed data use one decimal place, round the confidence interval limits accordingly."b. Identify the best point estimate of μ and the margin of error.
c. In constructing the confidence interval estimate of μ, why is it not necessary to confirm that the sample data appear to be from a population with a normaldistribution?
A. Because the sample standard deviation is known, the normal distribution can be used to construct the confidence interval.
B. Because the sample is a random sample, it can be assumed that the sample mean is from a population with a normal distribution.
C. Because the population standard deviation is known, the normal distribution can be used to construct the confidence interval.
D. Because the sample size of 50 is greater than 30, it can be assumed that the sample mean is from a population with a normal distribution.

it is not necessary to confirm that the sample data appear to be from a population with a normal distribution;

D. Because the sample size of 50 is greater than 30, it can be assumed that the sample mean is from a population with a normal distribution

Step-by-step explanation:

Normal distribution which is  otherwise known as the Gaussian distribution, it is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

The arithmetic mean or average; is the sum of a collection of numbers divided by the total  numbers in the collection.

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explanation

the graph has a slope of 1/3 because each time you move up 1, you go to the right 3. so, slope = rise/run = 1/3. we can cross choice a off the list since we want a slope of 3, rather than 1/3.

the first table shown has a slope of -3. this is because the rise is -6 and the run is 2, so slope = rise/run = -6/2 = -3. note how x increases by 2 each time (run) and y drops by 6 each time (rise). choice b can be eliminated.

the second table has a slope of 3. each time x goes up by 1, the y values increase by 3. slope = rise/run = 3/1 = 3. alternatively you can use the slope formula to prove that the slope is 3 here. use any two rows of values to generate the two points. choice c is one of the answers

the third table also has a slope of 3. let's use the slope formula to prove as such. i'm going to use the first two rows of the table. so i'll use the two points (2,1) and (5,10)

m = slope

m = (y2-y1)/(x2-x1)

m = (10-1)/(5-2)

m = 9/3

m = 3 so we get a slope of 3

choice d is the other answer