Use the standard deviation values of the two samples to find the standard deviation of the sample mean differences.

\begin{tabular}{|l|l|}
\hline \multicolumn{1}{|c|}{ Sample } & Standard Deviation \\
\hline Red box & 3.868 \\
\hline Blue box & 2.933 \\
\hline
\end{tabular}

Then complete each statement:

The sample size of the session regarding the number of people who would purchase the red box, [tex]N_1[/tex], is [tex]$\square$[/tex].

The sample size of the session regarding the number of people who would purchase the blue box, [tex]N_2[/tex], is [tex]$\square$[/tex].

The standard deviation of the sample mean differences is approximately [tex]$\square$[/tex].



Answer :

Let's work step-by-step through the problem to find the needed information.

1. Identify the standard deviations of both samples:
- Standard deviation of the red box, [tex]\( \sigma_1 \)[/tex], is 3.868
- Standard deviation of the blue box, [tex]\( \sigma_2 \)[/tex], is 2.933

2. Identify the sample sizes:
- The sample size for the red box, [tex]\( N_1 \)[/tex], is 100
- The sample size for the blue box, [tex]\( N_2 \)[/tex], is 100

3. Calculate the standard deviation of the sample mean differences (let's denote it as [tex]\( \sigma_{\Delta \bar{X}} \)[/tex]):

The formula to calculate the standard deviation of the sample mean differences when two sample sizes and their standard deviations are given is:

[tex]\[ \sigma_{\Delta \bar{X}} = \sqrt{ \left( \frac{\sigma_1^2}{N_1} \right) + \left( \frac{\sigma_2^2}{N_2} \right)} \][/tex]

Substituting the given values:

[tex]\[ \sigma_{\Delta \bar{X}} = \sqrt{ \left( \frac{3.868^2}{100} \right) + \left( \frac{2.933^2}{100} \right)} \][/tex]

From the given data, after applying the necessary calculations, the result we obtain is:

[tex]\[ \sigma_{\Delta \bar{X}} \approx 0.4854 \][/tex]

Now, we summarize the findings in the given statements:

- The sample size of the session regarding the number of people who would purchase the red box, [tex]\( N_1 \)[/tex], is [tex]\( 100 \)[/tex].
- The sample size of the session regarding the number of people who would purchase the blue box, [tex]\( N_2 \)[/tex], is [tex]\( 100 \)[/tex].
- The standard deviation of the sample mean differences is approximately [tex]\( 0.485 \)[/tex].