Instruction 2 -Referring to Instruction 2

Short Answer

Instruction 2.7
The ordered array below resulted from taking a sample of 25 batches of 500 computer chips and determining how many in each batch were defective.
$$\begin{array}{l}\text { Defeds }\\\begin{array} { | l | l | l | l | l | l | l | l | l | l | l | l | l | } \hline 1 & 2 & 4 & 4 & 5 & 5 & 6 & 7 & 9 & 9 & 12 & 12 & 15 \\\hline 17 & 20 & 21 & 23 & 23 & 25 & 26 & 27 & 27 & 28 & 29 & 29 & \\\hline\end{array}\end{array}$$
-Referring to Instruction 2.7,if a frequency distribution for the defects data is constructed,using '0 but less than 5' as the first class,the frequency of the '20 but less than 25' class would be _________.