standard deviation

Question

x P(x)

0 0.05

1 0.1

2 0.25

3 0.6

Find the standard deviation of this probability distribution. Give your answer to at least 2 decimal places

Incorrect

Box 1: Enter your answer as a number (like 5, -3, 2.2172) or as a calculation (like 5/3, 2^3, 5+4)

Enter DNE for Does Not Exist, oo for Infinity

Answer 1

mean = sum x*P(x)

variance = [sum x^2 * P(x)] - mean^2

standard deviation = square root of variance

x P(x) x * P(x) x^2 x^2 * P(x)

0 0.05 0 0 0

1 0.1 0.1 1 0.1

2 0.25 0.5 4 1

3 0.6 1.8 9 5.4

2.4 = mean 6.5 - mean **2 = 0.74 = variance --> standard deviation = 0.8602