Measures of the Spread of the Data · Exercise 9

Find the standard deviation for the following frequency tables using the formula. Check the calculations with the TI 83/84.

(a) $$\begin{array}{cc}\text{Grade}& \text{Frequency}\\ \text{49.5–59.5}& \text{2}\\ \text{59.5–69.5}& \text{3}\\ \text{69.5–79.5}& \text{8}\\ \text{79.5–89.5}& \text{12}\\ \text{89.5–99.5}& \text{5}\end{array}$$
(b) $$\begin{array}{cc}\text{Daily Low Temperature}& \text{Frequency}\\ \text{49.5–59.5}& \text{53}\\ \text{59.5–69.5}& \text{32}\\ \text{69.5–79.5}& \text{15}\\ \text{79.5–89.5}& \text{1}\\ \text{89.5–99.5}& \text{0}\end{array}$$
(c) $$\begin{array}{cc}\text{Points per Game}& \text{Frequency}\\ \text{49.5–59.5}& \text{14}\\ \text{59.5–69.5}& \text{32}\\ \text{69.5–79.5}& \text{15}\\ \text{79.5–89.5}& \text{23}\\ \text{89.5–99.5}& \text{2}\end{array}$$

OpenStax, Statistics · §2.7 Measures of the Spread of the Data · Exercise 9