Question

Thirty children were asked about the number of hours they watched TV programmes in the previous week. The results were found as follows:
$\begin{array}{cccccccccc}1& 6& 2& 3& 5& 12& 5& 8& 4& 8\\ 10& 3& 4& 12& 2& 8& 15& 1& 17& 6\\ 3& 2& 8& 5& 9& 6& 8& 7& 14& 12\end{array}$
Make a grouped frequency distribution table for this data, taking class width as 5 and one of the class intervals as 5- 10.

• A. $\begin{array}{cc}Hours& Numberofchildren\\ 0-5& 11\\ 5-10& 12\\ 10-15& 5\\ 15-20& 2\\ Total& 30\end{array}$
  
• B. $\begin{array}{cc}Hours& Numberofchildren\\ 0-5& 10\\ 5-10& 13\\ 10-15& 5\\ 15-20& 2\\ Total& 30\end{array}$
• C. $\begin{array}{cc}Hours& Numberofchildren\\ 0-5& 10\\ 5-10& 14\\ 10-15& 4\\ 15-20& 2\\ Total& 30\end{array}$
• D. None of the above

Answer 1

The correct option is B

$\begin{array}{cc}Hours& Numberofchildren\\ 0-5& 10\\ 5-10& 13\\ 10-15& 5\\ 15-20& 2\\ Total& 30\end{array}$

Our class intervals will be 0−5, 5− 10,10 −15…..
The grouped frequency distribution table can be constructed as follows.
$\begin{array}{cc}Hours& Numberofchildren\\ 0-5& 10\\ 5-10& 13\\ 10-15& 5\\ 15-20& 2\\ Total& 30\end{array}$

In the above frequency table the classes are continuous. So, the values that belongs to a class should be greater than or equal to the lower class but shold be less than the upper class.
Example: The value 10 will belong to the class 10-15 but not in 5-10.