What does ( 7.8 x 10 to the 3rd) x (1.0 x 10 to the 4th) equal?

7.8 * 10^7

Step-by-step explanation:

Group coefficients together and exponents together to multiply numbers in scientific notation.

( 7.8  *  1 )  ( 10 ^3  * 10^4)

Multiply  7.8 times 1.

7.8 * (10^3 * 10^4)

Use the power rule  a^m * a^n = a^(m+n) to combine exponents. So, add 3 and 4

7.8 * 10^7

investment b is an ordinary annuity with $3,909.64 in the account after one year.

step-by-step explanation: