Answer:
a. False
b. False
c. False
d. True
Step-by-step explanation:
a. 4.25 x 10⁶ = 425,000 (false) should be 4,250,000
b. 6.38 x 10⁹ = 638,000,000,000 (false) should be 6,380,000,000
c. 5.11 x 10⁻² = 511 (false) should be 0.0511
d. 2.79 x 10⁻⁴ = 0.000279 (true)