Home / 619.61-855-383.90

Finding the Fourth Proportional to 619.61, 855 and 383.90

Calculator

Solution

The fourth proportional to 619.61, 855 and 383.90 is: 529.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.61 : 855 = 383.90 : x
  2. Step 2: Convert to fraction form
    619.61/855 = 383.90/x
  3. Step 3: Cross multiply
    619.61x = 855 × 383.90
  4. Step 4: Simplify right side
    619.61x = 328,230.23
  5. Step 5: Solve for x
    x = 328,230.23/619.61
  6. Step 6: Final answer
    x = 529.74

Related Problems

Find fourth proportional to 309.80, 427.50 and 191.95
Half scale
Find fourth proportional to 1,239.21, 1,710 and 767.79
Double scale
Find fourth proportional to 620.61, 856.38 and 384.90
Similar ratio
Find fourth proportional to 929.41, 1,282.50 and 575.84
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.