Find the Standard Deviation of the Data Summarized in the Given

question 161

Multiple Choice

Find the standard deviation of the data summarized in the given frequency distribution.
-The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Find the standard deviation. Round your answer to one decimal place.
$$\begin{array} { r | r } \begin{array} { r } \text { Waiting time } \\\text { (minutes) }\end{array} & \begin{array} { r } \text { Number of } \\\text { customer }\end{array} \\\hline 0 - 3 & 15 \\4 - 7 & 10 \\8 - 11 & 9 \\12 - 15 & 14 \\16 - 19 & 0 \\20 - 23 & 2\end{array}$$

• A) 5.5 min
• B) 7.0 min
• C) 5.3 min
• D) 5.8 min

---

Definitions:

Smoothing Constant

A coefficient used in exponential smoothing to weight the relevance of historical data.

Autoregressive Model

A statistical model that predicts future behavior based on past values.

Absolute Differences

Absolute differences involve calculating the absolute value of the difference between two numbers, emphasizing the magnitude of the difference without considering direction.

Seasonal Variation

Seasonal variation refers to periodic fluctuations in statistical data that occur at the same time every year, often due to the influence of social, economic, or environmental factors.