Answer:
4.4% of the population with IQ between 120 and 125.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 100
Standard Deviation, σ = 15
We are given that the distribution of IQ scores is a bell shaped distribution that is a normal distribution.
a) Let X be a person's IQ score.
Then, density functions for IQ scores is given by:

b) P(population with IQ between 120 and 125.)
Formula:



Answer:
t(c) = 3.355
Step-by-step explanation:
We assume a normal distribution, and with sample size n = 9 we should follow a t -student test on both tails since the FDA is interested in determining if the amount of drug absorbed is different from 3.5 micrograms.
Therefore if α = 0,01 that means that confidence interval is 99 % or 0,99
Finally with α/2 = 0,005 and 8 degrees of freedom we find in t-student table t(c) = 3.355
Answer:
55 mph
Step-by-step explanation:
First hour: 40 mph
Second, Third, Fourth hours:
180 miles / 3 hours = 60 mph
Average: 40 (hour 1) + 60 (hour 2) + 60 (hour 3) + 60 (hour 4) = 220 / 4 hours = 55 mph average
I hope this helps!