Home / 3,900-5,850-1,126.80

Finding the Fourth Proportional to 3,900, 5,850 and 1,126.80

Calculator

Solution

The fourth proportional to 3,900, 5,850 and 1,126.80 is: 1,690.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,900 : 5,850 = 1,126.80 : x
  2. Step 2: Convert to fraction form
    3,900/5,850 = 1,126.80/x
  3. Step 3: Cross multiply
    3,900x = 5,850 × 1,126.80
  4. Step 4: Simplify right side
    3,900x = 6,591,780
  5. Step 5: Solve for x
    x = 6,591,780/3,900
  6. Step 6: Final answer
    x = 1,690.20

Related Problems

Find fourth proportional to 1,950, 2,925 and 563.40
Half scale
Find fourth proportional to 7,800, 11,700 and 2,253.60
Double scale
Find fourth proportional to 3,901, 5,851.50 and 1,127.80
Similar ratio
Find fourth proportional to 5,850, 8,775 and 1,690.20
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.