Home / 613.80-920.74-511.81

Finding the Fourth Proportional to 613.80, 920.74 and 511.81

Calculator

Solution

The fourth proportional to 613.80, 920.74 and 511.81 is: 767.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.80 : 920.74 = 511.81 : x
  2. Step 2: Convert to fraction form
    613.80/920.74 = 511.81/x
  3. Step 3: Cross multiply
    613.80x = 920.74 × 511.81
  4. Step 4: Simplify right side
    613.80x = 471,243.94
  5. Step 5: Solve for x
    x = 471,243.94/613.80
  6. Step 6: Final answer
    x = 767.75

Related Problems

Find fourth proportional to 306.90, 460.37 and 255.91
Half scale
Find fourth proportional to 1,227.60, 1,841.48 and 1,023.62
Double scale
Find fourth proportional to 614.80, 922.24 and 512.81
Similar ratio
Find fourth proportional to 920.70, 1,381.11 and 767.72
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.