Home / 63.21-86.85-54.99

Finding the Fourth Proportional to 63.21, 86.85 and 54.99

Calculator

Solution

The fourth proportional to 63.21, 86.85 and 54.99 is: 75.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.21 : 86.85 = 54.99 : x
  2. Step 2: Convert to fraction form
    63.21/86.85 = 54.99/x
  3. Step 3: Cross multiply
    63.21x = 86.85 × 54.99
  4. Step 4: Simplify right side
    63.21x = 4,775.88
  5. Step 5: Solve for x
    x = 4,775.88/63.21
  6. Step 6: Final answer
    x = 75.56

Related Problems

Find fourth proportional to 31.61, 43.43 and 27.50
Half scale
Find fourth proportional to 126.42, 173.70 and 109.98
Double scale
Find fourth proportional to 64.21, 88.22 and 55.99
Similar ratio
Find fourth proportional to 94.82, 130.28 and 82.49
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.