The sample variance in the strength test values of 15 bricks is 6.89 (MN/m2 ) 2 with a mean of 6.92 MN/m2 . What is the range of the true mean value at the confidence interval of 90%

The range of true mean value is "".

Explanation:

The given values are:

Number of bricks,

n = 15

Variance,

σ² = 6.89 MN/m²

Mean,

90% confidence level,

z = 1.64

Now,

The margin of error will be:

=

On substituting the given values, we get

=

=

=

So,

Range of true mean value will be:

=  

=  

answer:

Explanation:

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