Home / 57.90-86.90-55.91

Finding the Fourth Proportional to 57.90, 86.90 and 55.91

Calculator

Solution

The fourth proportional to 57.90, 86.90 and 55.91 is: 83.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.90 : 86.90 = 55.91 : x
  2. Step 2: Convert to fraction form
    57.90/86.90 = 55.91/x
  3. Step 3: Cross multiply
    57.90x = 86.90 × 55.91
  4. Step 4: Simplify right side
    57.90x = 4,857.86
  5. Step 5: Solve for x
    x = 4,857.86/57.90
  6. Step 6: Final answer
    x = 83.90

Related Problems

Find fourth proportional to 28.95, 43.45 and 27.95
Half scale
Find fourth proportional to 115.80, 173.79 and 111.81
Double scale
Find fourth proportional to 58.90, 88.40 and 56.91
Similar ratio
Find fourth proportional to 86.85, 130.34 and 83.86
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.