Answer:
a
[tex]\= x = 82 [/tex]
b
[tex]s = 9.64 [/tex]
Step-by-step explanation:
From the question we are told that
The data is 87 91 86 82 72 91 60 77 80 79 83 96
Generally the point estimate for the mean is mathematically represented as
[tex]\= x = \frac{\sum x_i }{n}[/tex]
=> [tex]\= x = \frac{87 +91 + 86 + \cdots + 96}{12}[/tex]
=> [tex]\= x = 82 [/tex]
Generally the point estimate for the standard deviation is mathematically represented as
[tex]s = \sqrt{\frac{ \sum ( x_i - \= x )^2 }{ n -1 } }[/tex]
=> [tex]s = \sqrt{\frac{ ( 87 - 82 )^2 +( 91 - 82 )^2 + \cdots + ( 96 - 82 )^2 }{ 12 -1 } }[/tex]
=> [tex]s = 9.64 [/tex]
Part(a): The required mean is 82
Part(b): The required standard deviation is 9.639
Mean:
The mean is one of the measures of central tendency.
Part(a):
The formula for finding the mean is,
[tex]\bar{x}=\frac{\sum x_i}{n}[/tex]
Now, calculating the mean for the [tex]n=12[/tex] observation
[tex]\bar{x}=\frac{87+91+86+82+72+91+60+77+80+79+83+96}{12}\\ \bar{x}=82[/tex]
Part(b):
The formula for the standard deviation is,
[tex]S=\sqrt{\frac{\sum (x_i-\bar{x})^2}{n-1} }[/tex]
Substituting the given values into the above formula we get,
[tex]S=\sqrt{\frac{((87-82)^2+(91-82)^2)+(86-82)^2+(82-82)^2+(72-82)^2+(91-82)^2+(60-82)^2+(77-82)^2+...+(96-82)^2}{12-1} } \\S=9.639[/tex]
Learn more about the topic Mean:
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