Home / 403.90-605.10-208.72

Finding the Fourth Proportional to 403.90, 605.10 and 208.72

Calculator

Solution

The fourth proportional to 403.90, 605.10 and 208.72 is: 312.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.90 : 605.10 = 208.72 : x
  2. Step 2: Convert to fraction form
    403.90/605.10 = 208.72/x
  3. Step 3: Cross multiply
    403.90x = 605.10 × 208.72
  4. Step 4: Simplify right side
    403.90x = 126,296.47
  5. Step 5: Solve for x
    x = 126,296.47/403.90
  6. Step 6: Final answer
    x = 312.69

Related Problems

Find fourth proportional to 201.95, 302.55 and 104.36
Half scale
Find fourth proportional to 807.80, 1,210.20 and 417.44
Double scale
Find fourth proportional to 404.90, 606.60 and 209.72
Similar ratio
Find fourth proportional to 605.85, 907.65 and 313.08
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.