91影视

The distribution of frequencies of the blood platelet count of males is as follows:

The actual measure of the mean of the blood platelet count of males is 255.1(1000 cells/$渭L$ ).

The formula for midpoints using the upper and lower class limits is:

$x=\frac{\text{Upper}\text{limit}+\text{Lower}\text{limit}}{2}$

The formula for the mean of frequency distribution is:

$\stackrel{炉}{x}=\frac{鈭�\left(f脳x\right)}{鈭�f}$, where fdenotes the frequencies and xdenotes the midpoints of the classes.

Therefore, the values are tabulated as follows:

The mean is computed using the totals as follows:

Substitute the values in the formula to obtain:

$$\begin{gathered} \stackrel{炉}{x}=\frac{37576.5}{147} \\ =255.6224 \end{gathered}$$

Thus, the mean blood platelet count of males is 255.6(1000 cells / $渭L$).

The actual mean value is 255.1(1000 cells /$渭L$).

The tabulated or computed values are 255.6(1000 cells /$渭L$), which is different from 255.1, the actual value.

Thus, theactual mean value is different from the one computed from the frequency distribution.