Home / 239.40-359.13-129.78

Finding the Fourth Proportional to 239.40, 359.13 and 129.78

Calculator

Solution

The fourth proportional to 239.40, 359.13 and 129.78 is: 194.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    239.40 : 359.13 = 129.78 : x
  2. Step 2: Convert to fraction form
    239.40/359.13 = 129.78/x
  3. Step 3: Cross multiply
    239.40x = 359.13 × 129.78
  4. Step 4: Simplify right side
    239.40x = 46,607.89
  5. Step 5: Solve for x
    x = 46,607.89/239.40
  6. Step 6: Final answer
    x = 194.69

Related Problems

Find fourth proportional to 119.70, 179.57 and 64.89
Half scale
Find fourth proportional to 478.80, 718.26 and 259.56
Double scale
Find fourth proportional to 240.40, 360.63 and 130.78
Similar ratio
Find fourth proportional to 359.10, 538.70 and 194.67
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.