Home / 805.40-1,208.10-440.90

Finding the Fourth Proportional to 805.40, 1,208.10 and 440.90

Calculator

Solution

The fourth proportional to 805.40, 1,208.10 and 440.90 is: 661.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.40 : 1,208.10 = 440.90 : x
  2. Step 2: Convert to fraction form
    805.40/1,208.10 = 440.90/x
  3. Step 3: Cross multiply
    805.40x = 1,208.10 × 440.90
  4. Step 4: Simplify right side
    805.40x = 532,651.29
  5. Step 5: Solve for x
    x = 532,651.29/805.40
  6. Step 6: Final answer
    x = 661.35

Related Problems

Find fourth proportional to 402.70, 604.05 and 220.45
Half scale
Find fourth proportional to 1,610.80, 2,416.20 and 881.80
Double scale
Find fourth proportional to 806.40, 1,209.60 and 441.90
Similar ratio
Find fourth proportional to 1,208.10, 1,812.15 and 661.35
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.