Home / 104.20-143.98-78

Finding the Fourth Proportional to 104.20, 143.98 and 78

Calculator

Solution

The fourth proportional to 104.20, 143.98 and 78 is: 107.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    104.20 : 143.98 = 78 : x
  2. Step 2: Convert to fraction form
    104.20/143.98 = 78/x
  3. Step 3: Cross multiply
    104.20x = 143.98 × 78
  4. Step 4: Simplify right side
    104.20x = 11,230.44
  5. Step 5: Solve for x
    x = 11,230.44/104.20
  6. Step 6: Final answer
    x = 107.78

Related Problems

Find fourth proportional to 52.10, 71.99 and 39
Half scale
Find fourth proportional to 208.40, 287.96 and 156
Double scale
Find fourth proportional to 105.20, 145.36 and 79
Similar ratio
Find fourth proportional to 156.30, 215.97 and 117
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.