Home / 711.50-981.89-396.80

Finding the Fourth Proportional to 711.50, 981.89 and 396.80

Calculator

Solution

The fourth proportional to 711.50, 981.89 and 396.80 is: 547.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.50 : 981.89 = 396.80 : x
  2. Step 2: Convert to fraction form
    711.50/981.89 = 396.80/x
  3. Step 3: Cross multiply
    711.50x = 981.89 × 396.80
  4. Step 4: Simplify right side
    711.50x = 389,612.23
  5. Step 5: Solve for x
    x = 389,612.23/711.50
  6. Step 6: Final answer
    x = 547.59

Related Problems

Find fourth proportional to 355.75, 490.94 and 198.40
Half scale
Find fourth proportional to 1,423.00, 1,963.78 and 793.60
Double scale
Find fourth proportional to 712.50, 983.27 and 397.80
Similar ratio
Find fourth proportional to 1,067.25, 1,472.83 and 595.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.