Answer:
h. 36
Step-by-step explanation:
For a 68.26% confidence, z = 1.0.
Standard deviation (s) = 30 minutes
The sample size needed to assure that the sample mean does not differ from the true mean by more than 5 minutes is given by:
The sample size needed is 36.
Answer:
Step-by-step explanation:
To evaluate :
Solution:
Two negatives multiply to become a positive.
Thus, we can remove parenthesis by reversing the signs of the fraction by multiplying the negative outside.
⇒
Since the denominators are same for both fractions, so we simply add the numerators.
⇒
⇒ (Answer)