Algebra 2 The Normal Distribution Quiz: 10 Questions with Explanations

A 95%B 68%C 99.7%D 50%

The 68-95-99.7 rule: 95% within 2 standard deviations.

A 12B 3C 0.33D -3

z = (90 – 78) / 4 = 3.

A 2 standard deviations below the meanB 2 below the meanC 2% below the meanD 2 standard deviations above the mean

The sign shows the direction and the number counts standard deviations.

A 95%B 34%C 99.7%D 68%

The center region marked 68% is the data within one standard deviation.

A 62B 58C 65D 12

x = 50 + 1.5 · 8 = 62.

A 0.68B 0.34C 0.5D 1

The normal curve is symmetric, so half of the area is above the mean.

A Test B is better because 88 is greater than 82B They are equalC Test B is better because the sd is largerD Test A is better because z = 2 compared with z = 1

z-scores: A = (82 – 70)/6 = 2 and B = (88 – 80)/8 = 1, so A is higher relative to its class.

A 0.3%B 0.15%C 5%D 2.5%

99.7% are within 3 sd, leaving 0.3% in both tails, so 0.15% in the upper tail.

A 0.841B 0.318C 0.682D 0.159

0.841 – 0.159 = 0.682.

A Skewed to the rightB Symmetric and bell shaped with mean at the centerC Flat with equal heightsD Two separate peaks

A normal distribution is symmetric and bell shaped, with the mean, median, and mode at the center.