#### Answer

a) 6.974 x $10^{9}$
b) 1.344 x $10^{9}$
c) 1.1254 x $10^{7}$
d) 4.487 x $10^{6}$

#### Work Step by Step

a) The initial number must have the decimal moved to the left 9 times, because we move it to the left, the exponent is going to be positive and the answer is 6.974 x $10^{9}$
b) The initial number must have the decimal moved to the left 9 times, because we move it to the left, the exponent is going to be positive and the answer is 1.344 x $10^{9}$
c) The initial number must have the decimal moved to the left 7 times, because we move it to the left, the exponent is going to be positive and the answer is 1.1254 x $10^{7}$
d) The initial number must have the decimal moved to the left 6 times, because we move it to the left, the exponent is going to be positive and the answer is 4.487 x $10^{6}$