Step 1 :Round each number to 1 significant figure: \(791 \approx 800\) and \(153 \approx 200\)
Step 2 :Estimate the product: \(800 \times 200 = 160,000\)
Step 3 :\boxed{\text{a) The estimate for } 791 \times 153 \text{ is } 160,000}
Step 4 :Since both numbers were rounded up, the estimate is larger than the actual answer.
Step 5 :\boxed{\text{b) The estimate is larger than the actual answer}}