Home / 385.40-578-154.28

Finding the Fourth Proportional to 385.40, 578 and 154.28

Calculator

Solution

The fourth proportional to 385.40, 578 and 154.28 is: 231.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.40 : 578 = 154.28 : x
  2. Step 2: Convert to fraction form
    385.40/578 = 154.28/x
  3. Step 3: Cross multiply
    385.40x = 578 × 154.28
  4. Step 4: Simplify right side
    385.40x = 89,173.84
  5. Step 5: Solve for x
    x = 89,173.84/385.40
  6. Step 6: Final answer
    x = 231.38

Related Problems

Find fourth proportional to 192.70, 289 and 77.14
Half scale
Find fourth proportional to 770.80, 1,156 and 308.56
Double scale
Find fourth proportional to 386.40, 579.50 and 155.28
Similar ratio
Find fourth proportional to 578.10, 867 and 231.42
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.