For Each Company,calculate the Missing Amount

For each company,calculate the missing amount. $$\begin{array}{l}\begin{array} { l c r r r r } \text { Company } & \text { Sales } & \begin{array} { c } \text { Cost of }\\\text { Goods } \\\text { Sold }\end{array} & \begin{array} { l } \text { Gross } \\\text { Profit }\end{array} & \begin{array} { r } \text { Operating } \\\text { Expenses }\end{array} & \begin{array} { c } \text { Net } \\\text { Income }\end{array} \\\text { Lennon } & \$ 8,000 & \text { (a) } & \$ 4,000 & \$ 3,000 & \$ 1,000 \\\text { Harrison } & 9,000 & 3,000 & \text { (b) } & 2,000 & 4,000 \\\text { McCartney } & 8,000 & 3,000 & 5,000 & \text { (c) } & 2,000 \\\text { Starr } & 7,000 & 3,000 & 5,000 & 3,000 & \text { (d) }\end{array}\end{array}$$
$$\begin{array} { l r r r r r } { \text { Company } } & \text { Sales } & \begin{array} { r } \text { Cost of } \\\text { goods sold }\end{array} & \begin{array} { r } \text { Gross } \\\text { profit } ^ { \mathbf { a } }\end{array} & \begin{array} { r } \text { Operating } \\\text { expenses }\end{array} & \begin{array} { r } \text { Net } \\\text { income } ^ { \mathbf { b } }\end{array} \\\hline \text { Lennon } & \$ 8,000 & \underline { 4,000 } & \$ 4,000 & \$ 3,000 & \$ 1,000 \\\text { Harrison } & 9,000 & 3,000 & \underline { 6,000 } & 2,000 & 4,000 \\\text { McCartney } & 8,000 & 3,000 & 5,000 & \underline { 3,000 } & 2,000 \\\text { Starr } & 7,000 & 2,000 & 5,000 & 3,000 & \underline { 2,000 }\end{array}$$