$($a$)$ Find the average time for the $20$ basic cycles of the job. $\frac{619}{20}=30\mathrm{.}95$

$($b$)$ If the standard deviation for the $20$ basic cycles of the job is $2\mathrm{.}74($was found using a statistical calculator or Microsoft Excel$),$ determine if enough samples have been taken to be $95\%$ sure that the accuracy of the timestudy is within $5\%$ of the true mean value.

$n=[\{\frac{z}{a}\}\{\frac{s}{(\stackrel{}{x})}\}{]}^2=$

Enough samples? Yes x No $q,$

$($c$)$ Find the average time to move the finished goods. $2\mathrm{.}5$min $q,$ Since this job element only occurs with a frequency of $1$ in $10$ cycles, one$-$tenth of this time should be allocated to the overall job actual time.

Total actual time for job $=10$min

Actual average time for the assembly operation $q,$

Actual average time for moving goods $q,2\mathrm{.}5$min

Total actual time for job $=q,$

Accessibility: Good to go

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