Answer:
1.38
Step-by-step explanation:
The point estimate for the population standard deviation of the length of the walking canes is given as the squareroot of variance. Since variance is provided as 1.9 then the standard deviation will be
Therefore, rounded off to two decimal places, the standard deviation is approximately 1.38
Answer:
C. Decreases the margin of error and hence increases the precision
Step-by-step explanation:
If we select a sample by Simple Random Sampling in a population of “infinite” size (a population so large that we do not know its size exactly), then the margin of error is given by
where
<em>Z = The Z-score corresponding to the confidence level </em>
<em>S = The estimated standard deviation of the population </em>
<em>n = the size of the sample. </em>
As we can see, since n is in the denominator of the fraction and the numerator is kept constant, the larger the sample size the smaller the margin of error, so the correct choice is:
C. Decreases the margin of error and hence increases the precision