Home / 919-1,378.68-406

Finding the Fourth Proportional to 919, 1,378.68 and 406

Calculator

Solution

The fourth proportional to 919, 1,378.68 and 406 is: 609.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    919 : 1,378.68 = 406 : x
  2. Step 2: Convert to fraction form
    919/1,378.68 = 406/x
  3. Step 3: Cross multiply
    919x = 1,378.68 × 406
  4. Step 4: Simplify right side
    919x = 559,744.08
  5. Step 5: Solve for x
    x = 559,744.08/919
  6. Step 6: Final answer
    x = 609.08

Related Problems

Find fourth proportional to 459.50, 689.34 and 203
Half scale
Find fourth proportional to 1,838, 2,757.36 and 812
Double scale
Find fourth proportional to 920, 1,380.18 and 407
Similar ratio
Find fourth proportional to 1,378.50, 2,068.02 and 609
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.