Home / 429.96-645.24-285.72

Finding the Fourth Proportional to 429.96, 645.24 and 285.72

Calculator

Solution

The fourth proportional to 429.96, 645.24 and 285.72 is: 428.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.96 : 645.24 = 285.72 : x
  2. Step 2: Convert to fraction form
    429.96/645.24 = 285.72/x
  3. Step 3: Cross multiply
    429.96x = 645.24 × 285.72
  4. Step 4: Simplify right side
    429.96x = 184,357.97
  5. Step 5: Solve for x
    x = 184,357.97/429.96
  6. Step 6: Final answer
    x = 428.78

Related Problems

Find fourth proportional to 214.98, 322.62 and 142.86
Half scale
Find fourth proportional to 859.92, 1,290.48 and 571.44
Double scale
Find fourth proportional to 430.96, 646.74 and 286.72
Similar ratio
Find fourth proportional to 644.94, 967.86 and 428.58
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.