National Gears has a machining facility specializing in jobs for the two$-$wheeler components

market. The job$-$costing system follows two direct$-$cost categories $($direct materials and

direct manufacturing labor$)$ and a single indirect$-$cost pool $($manufacturing overhead,

allocated using direct labor$-$hours$).$ The indirect cost$-$allocation rate of the prior system

were Rs$.115$ per direct manufacturing labor$-$hour used in producing one item.

Recently, a team with members from product design, manufacturing, and accounting used

an activity$-$based approach to refine its job$-$costing system. The two direct$-$cost categories

were retained. The team decided to replace the single indirect$-$cost pool with five activity$-$

cost pools. These five activity$-$cost pools represent five activity areas at the facility, each

with its own supervisor and budget responsibility. Pertinent data are as follows:

Two representative jobs $($Job AB$41$ and Job AB$81)$ had the following activities

$1.$Compute the per unit manufacturing costs of each job under the prior job$-$costing system.

$2.$Compute the per unit manufacturing costs of each job under the activity$-$based job$-$costing

system.

$3.$Comment on the reasons for the difference in product costs. Do the above calculations in excel, attach excel screenshots and explain the steps and formulas, give explanation for $3$rd question too