Question

I couldn’t take a picture of question b) but it says “what is the probability that she selects all of those containing errors? This is unusual probability?(hint:WITHOUT REPLACEMENT)WRITE YOUR ANSWER IN PERCENT WITH ONE DECIMAL

Answer 1

The number of returns is

`=60`

The number of tax returns to be selected is

`=3`

The number of errors is

`=8`

The number of returns with no errors is

`\begin{gathered} =60-8 \\ =52 \end{gathered}`

The number of possible returns that the auditor can pick is

`=^(60)C_3=(60!)/(57!3!)=(60*59*58)/(6)=34220`

The number of those 3 returns with no errors will be

`=^(52)C_3=(52!)/(49!3!)=(52*51*50)/(6)=22100`

Hence,

The number of possible sets of 3 returns with no errors,

as a fraction of the number of possible sets of 3 returns available for auditing is

`\begin{gathered} =(22100)/(34220) \\ =0.646 \\ =0.646*100 \\ =64.6\% \end{gathered}`

Hence,

The final answer is

`\Rightarrow64.6\%`