Home / 501.21-691.66-280.15

Finding the Fourth Proportional to 501.21, 691.66 and 280.15

Calculator

Solution

The fourth proportional to 501.21, 691.66 and 280.15 is: 386.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    501.21 : 691.66 = 280.15 : x
  2. Step 2: Convert to fraction form
    501.21/691.66 = 280.15/x
  3. Step 3: Cross multiply
    501.21x = 691.66 × 280.15
  4. Step 4: Simplify right side
    501.21x = 193,768.55
  5. Step 5: Solve for x
    x = 193,768.55/501.21
  6. Step 6: Final answer
    x = 386.60

Related Problems

Find fourth proportional to 250.61, 345.83 and 140.08
Half scale
Find fourth proportional to 1,002.42, 1,383.32 and 560.30
Double scale
Find fourth proportional to 502.21, 693.04 and 281.15
Similar ratio
Find fourth proportional to 751.82, 1,037.49 and 420.23
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.