Home / 398.40-549.76-223.72

Finding the Fourth Proportional to 398.40, 549.76 and 223.72

Calculator

Solution

The fourth proportional to 398.40, 549.76 and 223.72 is: 308.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.40 : 549.76 = 223.72 : x
  2. Step 2: Convert to fraction form
    398.40/549.76 = 223.72/x
  3. Step 3: Cross multiply
    398.40x = 549.76 × 223.72
  4. Step 4: Simplify right side
    398.40x = 122,992.31
  5. Step 5: Solve for x
    x = 122,992.31/398.40
  6. Step 6: Final answer
    x = 308.72

Related Problems

Find fourth proportional to 199.20, 274.88 and 111.86
Half scale
Find fourth proportional to 796.80, 1,099.52 and 447.44
Double scale
Find fourth proportional to 399.40, 551.14 and 224.72
Similar ratio
Find fourth proportional to 597.60, 824.64 and 335.58
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.