You wish to estimate the average weight of a mouse. You obtain 10 mice, sampled uniformly at random and with replacement from the mouse population. Their weights are 21; 23; 27; 19; 17; 18; 20; 15; 17; 22 grams respectively. (a) What is the best estimate for the average weight of a mouse, from this data? (b) What is the standard error of this estimate? (c) How many mice would you need to reduce the standard error to 0.1?

Respuesta :

Answer:

a) 19.9

b) 1.1099

c) 1232

Step-by-step explanation:

We are given the following in the question:

21, 23, 27, 19, 17, 18, 20, 15, 17, 22

a) estimate for the average weight

[tex]Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}[/tex]

[tex]Mean =\displaystyle\frac{199}{10} = 19.9[/tex]

b) standard error of this estimate

Sum of squares of differences = 110.9

[tex]S.D = \sqrt{\dfrac{110.9}{9}} = 3.51[/tex]

Standard Error =

[tex]= \dfrac{s}{\sqrt{n}} = \dfrac{3.51}{\sqrt{10}} = 1.1099[/tex]

c) Sample size for a standard error of 0.1

[tex]0.1 = \dfrac{3.51}{\sqrt{n}} \\\\n = (\dfrac{3.51}{0.1})^2\\\\n = 1232.01[/tex]

Thus, the sample size must be approximately 1232 for a standard error of 0.1.

(a). The average weight of mouse is 19.9

(b). The standard error is 1.1099

(c). To reduce the standard error to 0.1 , number of mice need is 1232

Average of data:

The average weight of mouse is computed as divide sum of data  by total number of data.

       [tex]Average=\frac{21+23+27+19+17+18+20+15+17+22}{10} \\\\Average=\frac{199}{10}=19.9[/tex]

Standard deviation is,

                    [tex]S.D=\sqrt{\frac{110.9}{9} }=3.51\\ \\Error=\frac{S.D}{\sqrt{n} }=\frac{3.51}{\sqrt{10} }=1.1099[/tex]

Sample size is,

                  [tex]0.1=\frac{3.51}{\sqrt{n} } \\\\n=1232[/tex]

Learn more about the standard deviation here:

https://brainly.com/question/475676