The range of a data set is the difference between the greatest and the smallest values.

According to the plot, the smallest value is $\color{red}3$ and the greatest is ${\color{blue}6}.$

Therefore, the range of the data set is

\[ {\color{blue}\text{greatest}} - {\color{red}\text{smallest}} = {\color{blue}6} - {\color{red}3} = 3. \]

The range of a data set is the difference between the greatest and the smallest values.

According to the plot, the smallest value is ${\color{red}{1}}\,\textrm{kg}$ and the greatest is ${\color{blue}5}\,\textrm{kg}.$

Therefore, the range of the data set is

\[ {\color{blue}\text{greatest}} - {\color{red}\text{smallest}} = {\color{blue}5}\,\textrm{kg} - {\color{red}1}\,\textrm{kg} = 4\,\textrm{kg}. \]

The dot plot tells us the following:

• $\color{blue}2$ of the children read for $15$ minutes

• $\color{blue}1$ of the children reads for $30$ minutes

• $\color{blue}2$ of the children read for $45$ minutes

• $\color{blue}1$ of the children reads for $60$ minutes

So, we get the following data:

\[ 15, \: 15, \: 30, \: 45, \: 45, \: 60 \]

Now, we subtract the mean from each number in the data set, find the absolute value of the results, and add all these together:

\begin{align*} \vert 15-{\color{blue}35} \vert + \vert 15-{\color{blue}35} \vert + \vert 30-{\color{blue}35} \vert + \vert 45-{\color{blue}35} \vert + \vert 45-{\color{blue}35} \vert + \vert 60-{\color{blue}35} \vert&= \\[3pt] \vert -20 \vert + \vert -20 \vert + \vert -5 \vert + \vert \,10\, \vert + \vert \, 10\, \vert + \vert \, 25\, \vert &= \\[3pt] 20+ 20 + 5 + 10+10+25 &= \\[3pt] {\color{red}90} & \end{align*}

Finally, to calculate the mean absolute deviation (MAD), we divide the sum obtained above (${\color{red}90}$) by the total number of data points ($6$). This gives \[ \text{MAD} = \dfrac{\color{red}90}{6} = 15. \]

The dot plot tells us the following:

• there are $\color{blue}2$ values in the data set equal to $5$

• there is $\color{blue}1$ value in the data set equal to $10$

• there are $\color{blue}2$ values in the data set equal to $15$

So, we get the following data:

\[ 5, \: 5, \: 10, \: 15, \: 15 \]

Now, we find the mean of the data: \begin{align*} {\color{blue}\text{mean}} &= \dfrac{(5 \times {\color{blue}2}) + (10 \times {\color{blue}1}) + (15 \times {\color{blue}2})}{5}\\[5pt] &= \dfrac{50}{5} \\[5pt] &= {\color{blue}10} \end{align*}

Next, we subtract the mean from each number in the data set, find the absolute value of the results, and add all these together:

\begin{align*} \vert 5-{\color{blue}10} \vert + \vert 5-{\color{blue}10} \vert + \vert 10-{\color{blue}10} \vert + \vert 15-{\color{blue}10} \vert + \vert 15-{\color{blue}10} \vert &= \\[3pt] \vert -5 \vert + \vert -5 \vert + \vert \,0\, \vert + \vert \,5\, \vert + \vert \, 5\, \vert &= \\[3pt] 5+ 5 + 0 + 5+5 &= \\[3pt] {\color{red}20} & \end{align*}

Finally, to calculate the mean absolute deviation (MAD), we divide the sum obtained above (${\color{red}20}$) by the total number of data points ($5$). This gives \[ \text{MAD} = \dfrac{\color{red}20}{5} = 4. \]