Home / 347.91-521.89-128.47

Finding the Fourth Proportional to 347.91, 521.89 and 128.47

Calculator

Solution

The fourth proportional to 347.91, 521.89 and 128.47 is: 192.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    347.91 : 521.89 = 128.47 : x
  2. Step 2: Convert to fraction form
    347.91/521.89 = 128.47/x
  3. Step 3: Cross multiply
    347.91x = 521.89 × 128.47
  4. Step 4: Simplify right side
    347.91x = 67,047.28
  5. Step 5: Solve for x
    x = 67,047.28/347.91
  6. Step 6: Final answer
    x = 192.71

Related Problems

Find fourth proportional to 173.96, 260.95 and 64.23
Half scale
Find fourth proportional to 695.82, 1,043.79 and 256.94
Double scale
Find fourth proportional to 348.91, 523.39 and 129.47
Similar ratio
Find fourth proportional to 521.87, 782.84 and 192.70
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.