We have the following information about the number of TVs that we find in ten homes: $$$1, 2, 3, 4, 1, 2, 3, 1, 1, 2$$$ Find the arithmetical mean and then try to apply the method of grouped information to estimate the mean
See development and solution
Development:
Arithmetical mean:
$$\displaystyle \overline{x}=\frac{1+2+3+4+1+2+3+1+1+2}{10}=\frac{20}{10}=2$$
Method of grouped information:
$$\displaystyle \overline{x}=\frac{1\cdot 4+2 \cdot 3+3\cdot 2+4 \cdot 1}{4+3+2+1}=\frac{20}{10}=2$$
Solution:
$$\displaystyle \overline{x}=2$$
$$\displaystyle \overline{x}=\frac{1\cdot 4+2 \cdot 3+3\cdot 2+4 \cdot 1}{4+3+2+1}=\frac{20}{10}=2$$