Home / 538.40-807.60-394.40

Finding the Fourth Proportional to 538.40, 807.60 and 394.40

Calculator

Solution

The fourth proportional to 538.40, 807.60 and 394.40 is: 591.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.40 : 807.60 = 394.40 : x
  2. Step 2: Convert to fraction form
    538.40/807.60 = 394.40/x
  3. Step 3: Cross multiply
    538.40x = 807.60 × 394.40
  4. Step 4: Simplify right side
    538.40x = 318,517.44
  5. Step 5: Solve for x
    x = 318,517.44/538.40
  6. Step 6: Final answer
    x = 591.60

Related Problems

Find fourth proportional to 269.20, 403.80 and 197.20
Half scale
Find fourth proportional to 1,076.80, 1,615.20 and 788.80
Double scale
Find fourth proportional to 539.40, 809.10 and 395.40
Similar ratio
Find fourth proportional to 807.60, 1,211.40 and 591.60
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.