Home / 430.88-646.28-138.38

Finding the Fourth Proportional to 430.88, 646.28 and 138.38

Calculator

Solution

The fourth proportional to 430.88, 646.28 and 138.38 is: 207.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.88 : 646.28 = 138.38 : x
  2. Step 2: Convert to fraction form
    430.88/646.28 = 138.38/x
  3. Step 3: Cross multiply
    430.88x = 646.28 × 138.38
  4. Step 4: Simplify right side
    430.88x = 89,428.30
  5. Step 5: Solve for x
    x = 89,428.30/430.88
  6. Step 6: Final answer
    x = 207.55

Related Problems

Find fourth proportional to 215.44, 323.14 and 69.19
Half scale
Find fourth proportional to 861.75, 1,292.55 and 276.75
Double scale
Find fourth proportional to 431.88, 647.77 and 139.38
Similar ratio
Find fourth proportional to 646.31, 969.41 and 207.56
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.