Home / 842.20-1,255.87-783.78

Finding the Fourth Proportional to 842.20, 1,255.87 and 783.78

Calculator

Solution

The fourth proportional to 842.20, 1,255.87 and 783.78 is: 1,168.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.20 : 1,255.87 = 783.78 : x
  2. Step 2: Convert to fraction form
    842.20/1,255.87 = 783.78/x
  3. Step 3: Cross multiply
    842.20x = 1,255.87 × 783.78
  4. Step 4: Simplify right side
    842.20x = 984,322.06
  5. Step 5: Solve for x
    x = 984,322.06/842.20
  6. Step 6: Final answer
    x = 1,168.75

Related Problems

Find fourth proportional to 421.10, 627.94 and 391.89
Half scale
Find fourth proportional to 1,684.40, 2,511.74 and 1,567.55
Double scale
Find fourth proportional to 843.20, 1,257.36 and 784.78
Similar ratio
Find fourth proportional to 1,263.30, 1,883.81 and 1,175.66
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.