Home / 318.78-439.65-208.17

Finding the Fourth Proportional to 318.78, 439.65 and 208.17

Calculator

Solution

The fourth proportional to 318.78, 439.65 and 208.17 is: 287.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.78 : 439.65 = 208.17 : x
  2. Step 2: Convert to fraction form
    318.78/439.65 = 208.17/x
  3. Step 3: Cross multiply
    318.78x = 439.65 × 208.17
  4. Step 4: Simplify right side
    318.78x = 91,521.94
  5. Step 5: Solve for x
    x = 91,521.94/318.78
  6. Step 6: Final answer
    x = 287.10

Related Problems

Find fourth proportional to 159.39, 219.83 and 104.09
Half scale
Find fourth proportional to 637.56, 879.30 and 416.34
Double scale
Find fourth proportional to 319.78, 441.03 and 209.17
Similar ratio
Find fourth proportional to 478.17, 659.48 and 312.26
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.