Instruction 3-3
the Stem-And-Leaf Display Below Represents the Number of Vitamin

question 97

Short Answer

Instruction 3-3
The stem-and-leaf display below represents the number of vitamin supplements sold by a health food store in a sample of 16 days.
$$\begin{array} { | l | l | } \hline \text { Stem } & \text { Leaves } \\\hline \text { 1H } & 99 \\\hline \text { 2L } & 0023 \\\hline \text { 2H } & 567 \\\hline \text { 3L } & 034 \\\hline \text { 3H } & 568 \\\hline \text { 4L } & 1 \\\hline\end{array}$$ Note (1): 1H means the "high teens" = 15, 16, 17, 18, or 19; 2L means the "low twenties" = 20, 21, 22, 23, or 24; 2H means the "high twenties" = 25, 26, 27, 28, or 29, etc.
Note (2): For this sample, the sum of the observations is 448, the sum of the squares of the observations is 13,356, and the sum of the squared differences between each observation and the mean is 812.
-Referring to Instruction 3-3,the standard deviation of the number of vitamin supplements sold in this sample is _____________ .

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Definitions:

Smoothing Constant

A parameter used in exponential smoothing methods that determines the level of smoothing applied to the data.

Seasonal Variation

Fluctuations in data or economic activity that occur regularly based on the season or time of year.

Time Series

It is a sequence of data points indexed in time order, often used to analyze and predict future events based on past trends.

Moving Average

A calculation to analyze data points by creating averages of different subsets of the complete data set.