Home / 518.71-778.37-287.79

Finding the Fourth Proportional to 518.71, 778.37 and 287.79

Calculator

Solution

The fourth proportional to 518.71, 778.37 and 287.79 is: 431.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.71 : 778.37 = 287.79 : x
  2. Step 2: Convert to fraction form
    518.71/778.37 = 287.79/x
  3. Step 3: Cross multiply
    518.71x = 778.37 × 287.79
  4. Step 4: Simplify right side
    518.71x = 224,005.66
  5. Step 5: Solve for x
    x = 224,005.66/518.71
  6. Step 6: Final answer
    x = 431.85

Related Problems

Find fourth proportional to 259.35, 389.18 and 143.90
Half scale
Find fourth proportional to 1,037.42, 1,556.73 and 575.58
Double scale
Find fourth proportional to 519.71, 779.87 and 288.79
Similar ratio
Find fourth proportional to 778.06, 1,167.55 and 431.69
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.