Answer:
97
Step-by-step explanation:
We are asked to find the size of sample to be 95% confident that the error in psychologist estimate of mean reaction time will not exceed 0.01 seconds.
We will use following formula to solve our given problem.
, where,
,
,
.


Substitute given values:





Therefore, the sample size must be 97 in order to be 95% confident that the error in his estimate of mean reaction time will not exceed 0.01 seconds.
Answer:
200 per hour 800 in 4 hours
Step-by-step explanation:
I assume you mean -x^3 + 4x + 3
so what you need is 4x + 3 > x^3
the only whole number it could be is 2 because 2x2x2 +3 > 2x2x2