Home / 191.57-287.35-81.91

Finding the Fourth Proportional to 191.57, 287.35 and 81.91

Calculator

Solution

The fourth proportional to 191.57, 287.35 and 81.91 is: 122.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    191.57 : 287.35 = 81.91 : x
  2. Step 2: Convert to fraction form
    191.57/287.35 = 81.91/x
  3. Step 3: Cross multiply
    191.57x = 287.35 × 81.91
  4. Step 4: Simplify right side
    191.57x = 23,536.99
  5. Step 5: Solve for x
    x = 23,536.99/191.57
  6. Step 6: Final answer
    x = 122.87

Related Problems

Find fourth proportional to 95.78, 143.67 and 40.96
Half scale
Find fourth proportional to 383.13, 574.70 and 163.82
Double scale
Find fourth proportional to 192.57, 288.85 and 82.91
Similar ratio
Find fourth proportional to 287.35, 431.02 and 122.87
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.