Home / 104.20-143.80-79.60

Finding the Fourth Proportional to 104.20, 143.80 and 79.60

Calculator

Solution

The fourth proportional to 104.20, 143.80 and 79.60 is: 109.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    104.20 : 143.80 = 79.60 : x
  2. Step 2: Convert to fraction form
    104.20/143.80 = 79.60/x
  3. Step 3: Cross multiply
    104.20x = 143.80 × 79.60
  4. Step 4: Simplify right side
    104.20x = 11,446.48
  5. Step 5: Solve for x
    x = 11,446.48/104.20
  6. Step 6: Final answer
    x = 109.85

Related Problems

Find fourth proportional to 52.10, 71.90 and 39.80
Half scale
Find fourth proportional to 208.40, 287.60 and 159.20
Double scale
Find fourth proportional to 105.20, 145.18 and 80.60
Similar ratio
Find fourth proportional to 156.30, 215.70 and 119.40
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.