Home / 342-511.20-280.80

Finding the Fourth Proportional to 342, 511.20 and 280.80

Calculator

Solution

The fourth proportional to 342, 511.20 and 280.80 is: 419.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    342 : 511.20 = 280.80 : x
  2. Step 2: Convert to fraction form
    342/511.20 = 280.80/x
  3. Step 3: Cross multiply
    342x = 511.20 × 280.80
  4. Step 4: Simplify right side
    342x = 143,544.96
  5. Step 5: Solve for x
    x = 143,544.96/342
  6. Step 6: Final answer
    x = 419.72

Related Problems

Find fourth proportional to 171, 255.60 and 140.40
Half scale
Find fourth proportional to 684, 1,022.40 and 561.60
Double scale
Find fourth proportional to 343, 512.69 and 281.80
Similar ratio
Find fourth proportional to 513, 766.80 and 421.20
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.