Table 71 Contains Short-Run Cost Date for Four Different Plants Sizes

Table 7.1 contains short-run cost date for four different plants sizes for Jackson's Jazz Instruments. $$\begin{array}{l}\text { Table } 7.1\\\begin{array} { c c c c c } \hline \text { Output } & \text { Plant 1 } & \text { Plant 2 } & \text { Plant } 3 & \text { Plant 4 } \\\hline 100 & 90 & 95 & 100 & 130 \\200 & 70 & 80 & 90 & 115 \\300 & 90 & 65 & 70 & 90 \\400 & 110 & 80 & 60 & 70 \\500 & 130 & 95 & 70 & 55 \\600 & 150 & 125 & 80 & 65 \\\hline\end{array}\end{array}$$ a) What is the best size of plant for each of the following level of output?
i. 200
ii. 300
iii. 400
iv. 500
b) Is Jackson's Jazz Instruments experiencing economies, diseconomies, or constant return to scale?