Below is the normal distribution curve for height (inches) of NBA basketball players. If there are 4500 NBA players, approximately how many of them are taller than 91 inches?(Round to nearest whole number)

Explanation:

From the given info, we see that 91 is two standard deviations above the mean. The diagram shows 91 is two tickmarks to the right of center. Or we could note that z = (x-mu)/sigma = (91-75)/8 = 2.

Roughly 95% of the normal distribution is within 2 standard deviations of the mean. I'm using the Empirical Rule.

So about 95% of the population is between 59 and 91 inches tall. That leaves 5% of the population in both tails combined. Cut this in half to get 2.5%

We have 2.5% of the population taller than 91 inches

2.5% of 4500 = 0.025*4500 = 112.5 = 113

Roughly 113 people are taller than 91 inches

Side notes:

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option