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:3.75 hours
Step-by-step explanation:
We are given the retail price of desk as $320. The store takes 50% off of the retail price of desk, then its price would become half of the original.
So its new price would be $160.
Now it says that it takes an additional 20% off of all furniture on store's holiday sale. So we need to cut off 20% from new price $160.
Holiday discount = 20% of $160 = 0.2 × 160 = 32.
Final selling price would be = $160 - $32 = $128.
So $128 is the final answer.