A population of values has a normal distribution with mean = 43.5 and standard deviation =79.4. You intend to draw a random sample of size n=11.
Find the probability that a sample of size n=11 is randomly selected with a mean less than 62.7.
Ok so I did the x - u / o √n = .802005......so now what? I know what to do if the question says "mean greater than 62.7" but I can't figure out the less part. The answer is .7887 by the way but I don't know.... please please help
Find the probability that a sample of size n=11 is randomly selected with a mean less than 62.7.
Ok so I did the x - u / o √n = .802005......so now what? I know what to do if the question says "mean greater than 62.7" but I can't figure out the less part. The answer is .7887 by the way but I don't know.... please please help
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Your calculation of z value (+ 0.802005) is correct.
In order to find the required probability the area under the standard normal curve is to be obtained.
The area left to z = + 0.802005 indicates the required probability.
i.e., the area less than z = + 0.802005
The area left to z = 0 is 0.5000
The area between z = 0 and z = + 0.80 is 0.2881
Therefore required probability = 0.5000 + 0.2881 = 0.7881
If calculator is used I think the answer will be 0.7887
In order to find the required probability the area under the standard normal curve is to be obtained.
The area left to z = + 0.802005 indicates the required probability.
i.e., the area less than z = + 0.802005
The area left to z = 0 is 0.5000
The area between z = 0 and z = + 0.80 is 0.2881
Therefore required probability = 0.5000 + 0.2881 = 0.7881
If calculator is used I think the answer will be 0.7887