Home / 239.89-359.73-85.78

Finding the Fourth Proportional to 239.89, 359.73 and 85.78

Calculator

Solution

The fourth proportional to 239.89, 359.73 and 85.78 is: 128.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    239.89 : 359.73 = 85.78 : x
  2. Step 2: Convert to fraction form
    239.89/359.73 = 85.78/x
  3. Step 3: Cross multiply
    239.89x = 359.73 × 85.78
  4. Step 4: Simplify right side
    239.89x = 30,857.64
  5. Step 5: Solve for x
    x = 30,857.64/239.89
  6. Step 6: Final answer
    x = 128.63

Related Problems

Find fourth proportional to 119.95, 179.87 and 42.89
Half scale
Find fourth proportional to 479.78, 719.46 and 171.56
Double scale
Find fourth proportional to 240.89, 361.23 and 86.78
Similar ratio
Find fourth proportional to 359.84, 539.60 and 128.67
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.