Home / 1,219.80-1,830-354.20

Finding the Fourth Proportional to 1,219.80, 1,830 and 354.20

Calculator

Solution

The fourth proportional to 1,219.80, 1,830 and 354.20 is: 531.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,219.80 : 1,830 = 354.20 : x
  2. Step 2: Convert to fraction form
    1,219.80/1,830 = 354.20/x
  3. Step 3: Cross multiply
    1,219.80x = 1,830 × 354.20
  4. Step 4: Simplify right side
    1,219.80x = 648,186
  5. Step 5: Solve for x
    x = 648,186/1,219.80
  6. Step 6: Final answer
    x = 531.39

Related Problems

Find fourth proportional to 609.90, 915 and 177.10
Half scale
Find fourth proportional to 2,439.60, 3,660 and 708.40
Double scale
Find fourth proportional to 1,220.80, 1,831.50 and 355.20
Similar ratio
Find fourth proportional to 1,829.70, 2,745 and 531.30
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.