Home / 50.90-70.30-42.78

Finding the Fourth Proportional to 50.90, 70.30 and 42.78

Calculator

Solution

The fourth proportional to 50.90, 70.30 and 42.78 is: 59.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    50.90 : 70.30 = 42.78 : x
  2. Step 2: Convert to fraction form
    50.90/70.30 = 42.78/x
  3. Step 3: Cross multiply
    50.90x = 70.30 × 42.78
  4. Step 4: Simplify right side
    50.90x = 3,007.43
  5. Step 5: Solve for x
    x = 3,007.43/50.90
  6. Step 6: Final answer
    x = 59.09

Related Problems

Find fourth proportional to 25.45, 35.15 and 21.39
Half scale
Find fourth proportional to 101.80, 140.60 and 85.56
Double scale
Find fourth proportional to 51.90, 71.68 and 43.78
Similar ratio
Find fourth proportional to 76.35, 105.45 and 64.17
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.