Home / 308.19-428.06-299.55

Finding the Fourth Proportional to 308.19, 428.06 and 299.55

Calculator

Solution

The fourth proportional to 308.19, 428.06 and 299.55 is: 416.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    308.19 : 428.06 = 299.55 : x
  2. Step 2: Convert to fraction form
    308.19/428.06 = 299.55/x
  3. Step 3: Cross multiply
    308.19x = 428.06 × 299.55
  4. Step 4: Simplify right side
    308.19x = 128,225.37
  5. Step 5: Solve for x
    x = 128,225.37/308.19
  6. Step 6: Final answer
    x = 416.06

Related Problems

Find fourth proportional to 154.10, 214.03 and 149.78
Half scale
Find fourth proportional to 616.38, 856.12 and 599.10
Double scale
Find fourth proportional to 309.19, 429.45 and 300.55
Similar ratio
Find fourth proportional to 462.29, 642.09 and 449.33
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.