Materials and manufacturing labour variances, standard costs. Consider the following sclected data regarding the manufacture of a line of upholstered chairs:

Standards per Chair

Direct matcrials

$2$ square metres of input at $$10$ per square metre

Direci manufacturing labour

$0\mathrm{.}5$ hour of input at $$20$ per hour

The following data were compiled regarding actual performance: actual output units $($chairs$)$ produced, $20,000$; square metres of input purchased and used, $37,000$ ; price per square metre, $$10\mathrm{.}20$; direct manufacturing labour costs, $$176,400$; actual hours of input, $9,000$ ; labour price per hour, $$19\mathrm{.}60.$

Show your computations on the price and efficiency variances for direct materials and for direct manufacturing labour. Give a plausible explanation of why the variances occurred.