Home / 49.80-68.70-38.91

Finding the Fourth Proportional to 49.80, 68.70 and 38.91

Calculator

Solution

The fourth proportional to 49.80, 68.70 and 38.91 is: 53.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    49.80 : 68.70 = 38.91 : x
  2. Step 2: Convert to fraction form
    49.80/68.70 = 38.91/x
  3. Step 3: Cross multiply
    49.80x = 68.70 × 38.91
  4. Step 4: Simplify right side
    49.80x = 2,673.12
  5. Step 5: Solve for x
    x = 2,673.12/49.80
  6. Step 6: Final answer
    x = 53.68

Related Problems

Find fourth proportional to 24.90, 34.35 and 19.46
Half scale
Find fourth proportional to 99.60, 137.40 and 77.82
Double scale
Find fourth proportional to 50.80, 70.08 and 39.91
Similar ratio
Find fourth proportional to 74.70, 103.05 and 58.37
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.