Respuesta :
The sample mean of the weights at the birth of the randomly chosen infants is 7.6 pounds.
Given: The sample of seven infants was selected randomly and the weights are: {9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6} (in pounds)
What is a sample?
A sample can be defined as a part of something big or a whole. It can be some of the elements from a given set of elements.
For example: Let us consider the set of natural numbers. The set of natural numbers has an infinite number of elements in it. We choose some numbers from the set, say {2, 7, 9, 10, 99, 200, 234}. These chosen numbers are known as samples from the set of natural numbers.
What is the sample mean?
The sample mean is the average value of the samples or it is the mean of all the elements which exist in the given sample.
The sample mean is denoted by x⁻ which is pronounced as x bar.
The formula to calculate sample mean (x⁻) is:
Sample Mean (x⁻) = Summation of all the elements in the sample / Total number of elements in the sample.
x⁻ = ∑xₙ / n
where,
∑xₙ = Summation of all the elements in the sample
n = Total number of elements in the sample
x⁻ = Sample mean
Now let's solve the given question:
The given sample is {9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6}
The summation of the elements in the sample is:
∑xₙ = 9.0 + 7.3 + 6.0 + 8.8 + 6.8 + 8.4 + 6.6
∑xₙ = 52.9
The total number of elements in the sample is:
n = 7
Therefore, the sample mean (x⁻) is:
x⁻ = ∑xₙ / n
x⁻ = 52.9 / 7
x⁻ = 7.5571 ≈ 7.6
Hence the sample mean of the weights at the birth of the randomly chosen infants is 7.6 pounds.
Know more about "sample mean" here: https://brainly.com/question/14127076
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Disclaimer: The question is incomplete. The complete question is mentioned below:
Question: A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the sample mean?
