Home / 247.60-371.20-85.28

Finding the Fourth Proportional to 247.60, 371.20 and 85.28

Calculator

Solution

The fourth proportional to 247.60, 371.20 and 85.28 is: 127.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    247.60 : 371.20 = 85.28 : x
  2. Step 2: Convert to fraction form
    247.60/371.20 = 85.28/x
  3. Step 3: Cross multiply
    247.60x = 371.20 × 85.28
  4. Step 4: Simplify right side
    247.60x = 31,655.94
  5. Step 5: Solve for x
    x = 31,655.94/247.60
  6. Step 6: Final answer
    x = 127.85

Related Problems

Find fourth proportional to 123.80, 185.60 and 42.64
Half scale
Find fourth proportional to 495.20, 742.40 and 170.56
Double scale
Find fourth proportional to 248.60, 372.70 and 86.28
Similar ratio
Find fourth proportional to 371.40, 556.80 and 127.92
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.