Home / 423.20-634.72-206.64

Finding the Fourth Proportional to 423.20, 634.72 and 206.64

Calculator

Solution

The fourth proportional to 423.20, 634.72 and 206.64 is: 309.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    423.20 : 634.72 = 206.64 : x
  2. Step 2: Convert to fraction form
    423.20/634.72 = 206.64/x
  3. Step 3: Cross multiply
    423.20x = 634.72 × 206.64
  4. Step 4: Simplify right side
    423.20x = 131,158.54
  5. Step 5: Solve for x
    x = 131,158.54/423.20
  6. Step 6: Final answer
    x = 309.92

Related Problems

Find fourth proportional to 211.60, 317.36 and 103.32
Half scale
Find fourth proportional to 846.40, 1,269.44 and 413.28
Double scale
Find fourth proportional to 424.20, 636.22 and 207.64
Similar ratio
Find fourth proportional to 634.80, 952.08 and 309.96
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.