Home / 255.49-383.20-82.15

Finding the Fourth Proportional to 255.49, 383.20 and 82.15

Calculator

Solution

The fourth proportional to 255.49, 383.20 and 82.15 is: 123.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.49 : 383.20 = 82.15 : x
  2. Step 2: Convert to fraction form
    255.49/383.20 = 82.15/x
  3. Step 3: Cross multiply
    255.49x = 383.20 × 82.15
  4. Step 4: Simplify right side
    255.49x = 31,479.88
  5. Step 5: Solve for x
    x = 31,479.88/255.49
  6. Step 6: Final answer
    x = 123.21

Related Problems

Find fourth proportional to 127.75, 191.60 and 41.08
Half scale
Find fourth proportional to 510.98, 766.40 and 164.30
Double scale
Find fourth proportional to 256.49, 384.70 and 83.15
Similar ratio
Find fourth proportional to 383.24, 574.80 and 123.23
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.