Home / 251.36-347.28-209.78

Finding the Fourth Proportional to 251.36, 347.28 and 209.78

Calculator

Solution

The fourth proportional to 251.36, 347.28 and 209.78 is: 289.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    251.36 : 347.28 = 209.78 : x
  2. Step 2: Convert to fraction form
    251.36/347.28 = 209.78/x
  3. Step 3: Cross multiply
    251.36x = 347.28 × 209.78
  4. Step 4: Simplify right side
    251.36x = 72,852.40
  5. Step 5: Solve for x
    x = 72,852.40/251.36
  6. Step 6: Final answer
    x = 289.83

Related Problems

Find fourth proportional to 125.68, 173.64 and 104.89
Half scale
Find fourth proportional to 502.72, 694.56 and 419.56
Double scale
Find fourth proportional to 252.36, 348.66 and 210.78
Similar ratio
Find fourth proportional to 377.04, 520.92 and 314.67
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.