Home / 413.90-620.80-208.38

Finding the Fourth Proportional to 413.90, 620.80 and 208.38

Calculator

Solution

The fourth proportional to 413.90, 620.80 and 208.38 is: 312.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.90 : 620.80 = 208.38 : x
  2. Step 2: Convert to fraction form
    413.90/620.80 = 208.38/x
  3. Step 3: Cross multiply
    413.90x = 620.80 × 208.38
  4. Step 4: Simplify right side
    413.90x = 129,362.30
  5. Step 5: Solve for x
    x = 129,362.30/413.90
  6. Step 6: Final answer
    x = 312.55

Related Problems

Find fourth proportional to 206.95, 310.40 and 104.19
Half scale
Find fourth proportional to 827.79, 1,241.60 and 416.76
Double scale
Find fourth proportional to 414.90, 622.30 and 209.38
Similar ratio
Find fourth proportional to 620.84, 931.20 and 312.57
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.