Home / 397.09-547.81-280.81

Finding the Fourth Proportional to 397.09, 547.81 and 280.81

Calculator

Solution

The fourth proportional to 397.09, 547.81 and 280.81 is: 387.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    397.09 : 547.81 = 280.81 : x
  2. Step 2: Convert to fraction form
    397.09/547.81 = 280.81/x
  3. Step 3: Cross multiply
    397.09x = 547.81 × 280.81
  4. Step 4: Simplify right side
    397.09x = 153,830.53
  5. Step 5: Solve for x
    x = 153,830.53/397.09
  6. Step 6: Final answer
    x = 387.39

Related Problems

Find fourth proportional to 198.55, 273.91 and 140.41
Half scale
Find fourth proportional to 794.18, 1,095.62 and 561.62
Double scale
Find fourth proportional to 398.09, 549.19 and 281.81
Similar ratio
Find fourth proportional to 595.64, 821.72 and 421.22
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.