Answer:
a) 0.8413
b) 421
c) 
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 165
Standard Deviation, σ = 15
We are given that the distribution of IQ examination scores is a bell shaped distribution that is a normal distribution.
Formula:
a) P(IQ scores at most 180)
P(x < 180)
Calculation the value from standard normal z table, we have,
b) Number of the members of the club have IQ scores at most 180
n = 500

c) P(X< x) = 0.95
We have to find the value of x such that the probability is 0.95
Calculation the value from standard normal z table, we have,


You take away the 4 from the 8 which is equal to 4 then you have to barrow from the 2 to make the 4 to 14 and when you wait you are basically right your calculation is right
Convert the fractions so they both have the same denominator (bottom part of the fraction)
1/5 = 7/35
This is because 5*7=35, so 1*7=7
1/7 = 5/35
This is because 7*5=35, so 1*5 =5
Then subtract the top numbers to get the answer:
You need Pythagorean theorem for this.
a² + b² = c², where c is the hypotheneus and a and b are the sides of the right triangle.
24² + x² = 26²
x² = 676-576
x = ±√100
x = 10 (-10 is rejected because length of triangle cannot be a negative number)