To assess the accuracy of a laboratory scale, a standard weight known to weigh 1 gram is repeatedly weighed a total of n n times and the mean ¯ x x¯ of the weighings is computed. Suppose the scale readings are Normally distributed, with unknown mean m m and standard deviation σ = 0.01 σ=0.01 grams. How large should n n be so that a 95% confidence interval for m m has a margin of error of ± 0.0001 ±0.0001 ?

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Answer: 38416

Step-by-step explanation:

The formula to find the sample size in a normally distributed population :-

[tex]n=(\dfrac{z^*\times \sigma}{E})^2[/tex] , where  [tex]\sigma[/tex] = Population standard deviation from the prior study.

z* = critical z-value , E = Margin of error.

As per given , we have

The scale readings are Normally distributed, with unknown mean m m and standard deviation σ = 0.01 grams.

E =  ±0.0001

Critical z- value for  95% confidence interval : z* = 1.96

Substitute all values in formula , we get

[tex]n=(\dfrac{1.96\times0.01}{0.0001 })^2\\\\=38416[/tex]

Hence, the minimum sample size should be 38416 .

The minimum sample size is 38416 and this can be determined by using the formula of the sample size in a normally distributed population.

Given :

  • To assess the accuracy of a laboratory scale, a standard weight known to weigh 1 gram is repeatedly weighed a total of n n times and the mean of the weighings is computed.
  • Suppose the scale readings are Normally distributed, with unknown mean m and standard deviation σ = 0.01 grams.

The formula of the sample size is given by:

[tex]\rm n=\left({\dfrac{z\times \sigma}{E}} \right)^2[/tex]

where [tex]\sigma[/tex] is the standard deviation, z is the critical z-value, and E is the margin of error.

Now, substitute the values known terms in the above formula.

[tex]\rm n=\left({\dfrac{1.96\times 0.01}{0.0001}} \right)^2[/tex]

Simplifying the above expression in order to determine the value of 'n'.

n = 38416

So, the minimum sample size is 38416.

For more information, refer to the link given below:

https://brainly.com/question/21344417