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Obesity rate standard deviation and average obesity percentage are best estimates. Also, to determine the difference between the obesity rate in the United States and the global obesity rate.

The given percentage obesity rate class and number of countries under each class.

Calculation:

The estimate of average obesity percentage for countries is sample mean. The formula to find sample mean from frequency table is

Sample mean$\stackrel{炉}{x}=\frac{鈭�f{x}_m}{n}$

Where

$\mathrm{f}=$class frequency,

$x_m=$class midpoint and

$\mathrm{n}=$total frequency

The formula to find standard deviation for grouped frequency data is

Standard deviationrole="math" localid="1648086234307" $\mathrm{s}=\sqrt{\frac{鈭�{f_{x_m}}^2}{n}-{\stackrel{炉}{x}}^2}$

consider the table:

Calculate the sample mean:

$\begin{array}{r}\stackrel{炉}{x}=\frac{鈭�f{x}_m}{n}\\ =\frac{1165.775}{50}\\ =23.3155\end{array}$

So, sample mean = $23.3155$

To calculate standard deviation the formula is shown below:

$s=\sqrt{\frac{鈭�f{x}^2}{n}-{\stackrel{炉}{x}}^2}$

Substitute values as shown below:

role="math" localid="1648086750018" $$\begin{gathered} s=\sqrt{\frac{鈭�f{x}^2}{n}-{\stackrel{炉}{x}}^2} \\ \begin{array}{r}=\sqrt{\frac{35403.1}{50}鈭�(23.32{)}^2}\\ =\sqrt{708.062鈭�543.8224}\\ =12.82\end{array} \end{gathered}$$

Hence the value standard deviation = 12.82

The average obesity rate in the United States is 33.9 percent. For the given countries, the average rate is 23.3155. The average obesity rate in the United States is higher than other countries.