1. ## basic matrix

Matrices
Matrix P shows the no. of pizzas a local pizza parlor sold over a 2 week period. Matrix D shows the revenues of and advetising fees in dollars per pizza.

No of pizzas sold
P= cheese bacon 'shrooms
{231 182 168}
{241 206 132}

No of pizzas sold
[ 2.69 .23 ]
[ 2.71 .25 ]
[ 2.84 .29 ]
If matrix K is the product of p and d, which elelment in matrix k represents the total advertising fees for week one?

K= (P)(D)=
[ P11 P12]
[ P21 P22]

I'm guessing that this is more of a basic matrices knowledge question..
Either that or i'd have to multiply the matrices by hand -yuck, how tedious-and choose an answer based on the looks of things.

I need help...

..(I need somebody-HELP! Not just anybody-HELP!.. )

2. Originally Posted by TNB
Matrices
Matrix P shows the no. of pizzas a local pizza parlor sold over a 2 week period. Matrix D shows the revenues of and advetising fees in dollars per pizza.

No of pizzas sold
P= cheese bacon 'shrooms
week 1:[231 182 168]
week 2:[241 206 132]

No of pizzas sold
[ 2.69 .23 ]
[ 2.71 .25 ]
[ 2.84 .29 ]

If matrix K is the product of p and d, which elelment in matrix k represents the total advertising fees for week one?

K= (P)(D)=
[ P11 P12]
[ P21 P22]
Hello TNB,

That would be P12. Here's your product matrix.

week 1:[1591.73 147.35]
week 2:[1581.43 145.21]

3. Originally Posted by TNB
Matrices
Matrix P shows the no. of pizzas a local pizza parlor sold over a 2 week period. Matrix D shows the revenues of and advetising fees in dollars per pizza.

No of pizzas sold
P= cheese bacon 'shrooms
{231 182 168}
{241 206 132}

No of pizzas sold
[ 2.69 .23 ]
[ 2.71 .25 ]
[ 2.84 .29 ]
If matrix K is the product of p and d, which elelment in matrix k represents the total advertising fees for week one?

K= (P)(D)=
[ P11 P12]
[ P21 P22]

I'm guessing that this is more of a basic matrices knowledge question..
Either that or i'd have to multiply the matrices by hand -yuck, how tedious-and choose an answer based on the looks of things.

I need help...

..(I need somebody-HELP! Not just anybody-HELP!.. )
You don't have to do the complete multiplication. What you are looking for is the result of

first row of P * second column of D = P12

I'll leave the rest for you.

EDIT: Too fast for me, masters.

4. What do the rows of the first matrix indicate, numbers sold or week in which sold?

What do the columns of the second matrix indicate?

You need the sum of the form (number of type sold)*(cost to advertise that type that week) + (number of another type sold)*(cost to advertise that type that week) + (number of last type sold)*(cost to advertise that type that week).

So which row of P must be multiplied by which column of D? Which entry of K matches this product?

Have fun!