The normal distributions for three different SAT examinations is displayed above what can you conclude about the standard deviations of the three exams?

Comparing the standard deviations of each distribution, you have blue < red < yellow.

For any normally distributed random variable X with mean µ and standard deviation σ, we have the property that

Pr[|X - µ| ≤ σ] ≈ 68%

In other words, roughly 68% of a normal distribution lies within 1 standard deviation of the mean. This means the plot of the density of a distribution with a smaller standard deviation forms a tighter peak (like the blue curve), whereas a larger standard deviation would be indicated by a more dispersed, flattened curve (like the yellow one).

bfgbh bhf gfdzf bhgfrdfgbn cvdgsytrghvn ncvhgfdtrseawa hgdrsxcvbgfrewq

step-by-step explanation:

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb