Home / 625.81-863.64-389.90

Finding the Fourth Proportional to 625.81, 863.64 and 389.90

Calculator

Solution

The fourth proportional to 625.81, 863.64 and 389.90 is: 538.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    625.81 : 863.64 = 389.90 : x
  2. Step 2: Convert to fraction form
    625.81/863.64 = 389.90/x
  3. Step 3: Cross multiply
    625.81x = 863.64 × 389.90
  4. Step 4: Simplify right side
    625.81x = 336,729.65
  5. Step 5: Solve for x
    x = 336,729.65/625.81
  6. Step 6: Final answer
    x = 538.07

Related Problems

Find fourth proportional to 312.90, 431.82 and 194.95
Half scale
Find fourth proportional to 1,251.62, 1,727.28 and 779.79
Double scale
Find fourth proportional to 626.81, 865.02 and 390.90
Similar ratio
Find fourth proportional to 938.71, 1,295.46 and 584.84
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.