Home / 442.40-662.80-391.20

Finding the Fourth Proportional to 442.40, 662.80 and 391.20

Calculator

Solution

The fourth proportional to 442.40, 662.80 and 391.20 is: 586.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    442.40 : 662.80 = 391.20 : x
  2. Step 2: Convert to fraction form
    442.40/662.80 = 391.20/x
  3. Step 3: Cross multiply
    442.40x = 662.80 × 391.20
  4. Step 4: Simplify right side
    442.40x = 259,287.36
  5. Step 5: Solve for x
    x = 259,287.36/442.40
  6. Step 6: Final answer
    x = 586.09

Related Problems

Find fourth proportional to 221.20, 331.40 and 195.60
Half scale
Find fourth proportional to 884.80, 1,325.60 and 782.40
Double scale
Find fourth proportional to 443.40, 664.30 and 392.20
Similar ratio
Find fourth proportional to 663.60, 994.20 and 586.80
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.