Answer:
C. ± 2.326 years.
Step-by-step explanation:
We have the standard deviation for the sample. So we use the t-distribution to solve this question.
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so ![z = 2.326/tex]Now, find the width of the interval[tex]W = z*\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=z%20%3D%202.326%2Ftex%5D%3C%2Fp%3E%3Cp%3E%3Cstrong%3ENow%3C%2Fstrong%3E%2C%20find%20the%20width%20of%20the%20interval%3C%2Fp%3E%3Cp%3E%5Btex%5DW%20%3D%20z%2A%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
In which 
is the standard deviation of the population and n is the size of the sample.
In this question:
So
The correct answer is:
C. ± 2.326 years.
1/3 chance to pick a boy 2/3 chance to pick a girl
It refers to the number of times a number is being multiplied by itself ... Ex: two to the fourth power
4 would be the exponent
Answer: 42.9%
Step-by-step explanation:
Percent error is the difference between the measured and known value, which is divided by the known value, and then multiplied by 100%.
Percent error = (Estimated number- Actual number)/Actual Number × 100.
= (60 - 42)/42 × 100
= 18/42 × 100
= 0.429 × 100
= 42.9%
