Home / 381.78-571.86-218.70

Finding the Fourth Proportional to 381.78, 571.86 and 218.70

Calculator

Solution

The fourth proportional to 381.78, 571.86 and 218.70 is: 327.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.78 : 571.86 = 218.70 : x
  2. Step 2: Convert to fraction form
    381.78/571.86 = 218.70/x
  3. Step 3: Cross multiply
    381.78x = 571.86 × 218.70
  4. Step 4: Simplify right side
    381.78x = 125,065.78
  5. Step 5: Solve for x
    x = 125,065.78/381.78
  6. Step 6: Final answer
    x = 327.59

Related Problems

Find fourth proportional to 190.89, 285.93 and 109.35
Half scale
Find fourth proportional to 763.56, 1,143.72 and 437.40
Double scale
Find fourth proportional to 382.78, 573.36 and 219.70
Similar ratio
Find fourth proportional to 572.67, 857.79 and 328.05
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.