Asked by Vanessa Green on Jun 24, 2024

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A population has a mean of 125 and a standard deviation of 16.A sample of 64 observations will be taken.The probability that the sample mean will be between 122.4 and 126.1 is

A) 0.1821.
B) 0.0919.
C) 0.6120.
D) 0.3880.

Sample Mean

The average value of a sample set of numbers, calculated by adding up all the observations and dividing by the number of observations.

  • Compute the likelihoods associated with mean and proportion estimates within the realm of inferential statistics.
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CM
Ciara MulieriJul 01, 2024
Final Answer :
C
Explanation :
First, we need to transform the sample mean to a z-score using the formula:

z = (x̄ - μ) / (σ / sqrt(n))

where x̄ is the sample mean, μ is the population mean, σ is the population standard deviation, and n is the sample size.

Using the values given in the problem, we have:

z1 = (122.4 - 125) / (16 / sqrt(64)) = -1.5
z2 = (126.1 - 125) / (16 / sqrt(64)) = 0.3875

Next, we need to find the probability of getting a z-score between -1.5 and 0.3875. We can use a standard normal distribution table or calculator to find these probabilities.

P(-1.5 < z < 0.3875) = 0.6120

Therefore, the answer is C.