Chapter 5 - Inner Product Spaces - 5.1 Length and Dot Product in Rn - 5.1 Exercises - Page 236: 78

$1.27895860 \times 10^6$ This means that the total income is $\$ 1.27895860 \times 10^6$.

The dot product of $u \cdot v$ is $$u \cdot v=4600\times 79.99+4290 \times 89.99+5250\times 99.99=1.27895860 \times 10^6$$ This means that the total income is $\$ 1.27895860 \times 10^6$.