Home / 306.55-422.31-208.18

Finding the Fourth Proportional to 306.55, 422.31 and 208.18

Calculator

Solution

The fourth proportional to 306.55, 422.31 and 208.18 is: 286.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.55 : 422.31 = 208.18 : x
  2. Step 2: Convert to fraction form
    306.55/422.31 = 208.18/x
  3. Step 3: Cross multiply
    306.55x = 422.31 × 208.18
  4. Step 4: Simplify right side
    306.55x = 87,916.50
  5. Step 5: Solve for x
    x = 87,916.50/306.55
  6. Step 6: Final answer
    x = 286.79

Related Problems

Find fourth proportional to 153.28, 211.16 and 104.09
Half scale
Find fourth proportional to 613.10, 844.62 and 416.36
Double scale
Find fourth proportional to 307.55, 423.69 and 209.18
Similar ratio
Find fourth proportional to 459.83, 633.47 and 312.27
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.