Home / 1,190.50-1,785.78-421

Finding the Fourth Proportional to 1,190.50, 1,785.78 and 421

Calculator

Solution

The fourth proportional to 1,190.50, 1,785.78 and 421 is: 631.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,190.50 : 1,785.78 = 421 : x
  2. Step 2: Convert to fraction form
    1,190.50/1,785.78 = 421/x
  3. Step 3: Cross multiply
    1,190.50x = 1,785.78 × 421
  4. Step 4: Simplify right side
    1,190.50x = 751,813.38
  5. Step 5: Solve for x
    x = 751,813.38/1,190.50
  6. Step 6: Final answer
    x = 631.51

Related Problems

Find fourth proportional to 595.25, 892.89 and 210.50
Half scale
Find fourth proportional to 2,381, 3,571.56 and 842
Double scale
Find fourth proportional to 1,191.50, 1,787.28 and 422
Similar ratio
Find fourth proportional to 1,785.75, 2,678.67 and 631.50
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.