Home / 561.60-775-312.91

Finding the Fourth Proportional to 561.60, 775 and 312.91

Calculator

Solution

The fourth proportional to 561.60, 775 and 312.91 is: 431.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.60 : 775 = 312.91 : x
  2. Step 2: Convert to fraction form
    561.60/775 = 312.91/x
  3. Step 3: Cross multiply
    561.60x = 775 × 312.91
  4. Step 4: Simplify right side
    561.60x = 242,501.38
  5. Step 5: Solve for x
    x = 242,501.38/561.60
  6. Step 6: Final answer
    x = 431.80

Related Problems

Find fourth proportional to 280.80, 387.50 and 156.45
Half scale
Find fourth proportional to 1,123.20, 1,550 and 625.81
Double scale
Find fourth proportional to 562.60, 776.38 and 313.91
Similar ratio
Find fourth proportional to 842.40, 1,162.50 and 469.36
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.