Home / 449.40-620.48-309.76

Finding the Fourth Proportional to 449.40, 620.48 and 309.76

Calculator

Solution

The fourth proportional to 449.40, 620.48 and 309.76 is: 427.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    449.40 : 620.48 = 309.76 : x
  2. Step 2: Convert to fraction form
    449.40/620.48 = 309.76/x
  3. Step 3: Cross multiply
    449.40x = 620.48 × 309.76
  4. Step 4: Simplify right side
    449.40x = 192,199.88
  5. Step 5: Solve for x
    x = 192,199.88/449.40
  6. Step 6: Final answer
    x = 427.68

Related Problems

Find fourth proportional to 224.70, 310.24 and 154.88
Half scale
Find fourth proportional to 898.80, 1,240.96 and 619.52
Double scale
Find fourth proportional to 450.40, 621.86 and 310.76
Similar ratio
Find fourth proportional to 674.10, 930.72 and 464.64
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.