Julia surveyed her friends to find the number of hours they spend on homework during the week. The data from her survey is displayed in the first table. She then took a random sample of five responses from the population as shown in the second table. Compare the mean of the population with the mean of the given sample.

\begin{tabular}{|l|l|l|l|l|}
\hline \multicolumn{5}{|c|}{Population Data} \\
\hline 4 & 5 & 3 & 1 & 3 \\
\hline 2 & 2 & 3 & 5 & 7 \\
\hline 3 & 6 & 3 & 0 & 1 \\
\hline 5 & 0 & 4 & 3 & 6 \\
\hline
\end{tabular}

\begin{tabular}{|l|l|l|l|l|}
\hline \multicolumn{5}{|c|}{Sample Data} \\
\hline 5 & 4 & 6 & 2 & 1 \\
\hline
\end{tabular}

What is the difference between the mean of the sample and the mean of the population?

A. 0.2
B. 0.3



Answer :

To solve this question, let's proceed step by step.

### Step 1: Calculate the mean of the population data

First, list out all the elements in the population data:
[tex]\[ 4, 5, 3, 1, 3, 2, 2, 3, 5, 7, 3, 6, 3, 0, 1, 5, 0, 4, 3, 6 \][/tex]

Next, sum all these numbers:
[tex]\[ 4 + 5 + 3 + 1 + 3 + 2 + 2 + 3 + 5 + 7 + 3 + 6 + 3 + 0 + 1 + 5 + 0 + 4 + 3 + 6 = 66 \][/tex]

Then, count the number of elements which is 20.

Now, calculate the mean of the population:
[tex]\[ \text{Mean of Population} = \frac{66}{20} = 3.3 \][/tex]

### Step 2: Calculate the mean of the sample data

List the sample data:
[tex]\[ 5, 4, 6, 2, 1 \][/tex]

Sum these numbers:
[tex]\[ 5 + 4 + 6 + 2 + 1 = 18 \][/tex]

Count the number of elements in the sample which is 5.

Now, calculate the mean of the sample:
[tex]\[ \text{Mean of Sample} = \frac{18}{5} = 3.6 \][/tex]

### Step 3: Compare the two means

The difference between the mean of the sample and the mean of the population is:
[tex]\[ \text{Difference} = 3.6 - 3.3 = 0.3 \][/tex]

Therefore, the difference between the mean of the sample and the mean of the population is:
[tex]\[ \boxed{0.3} \][/tex]

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