Home / 190-285-81.80

Finding the Fourth Proportional to 190, 285 and 81.80

Calculator

Solution

The fourth proportional to 190, 285 and 81.80 is: 122.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    190 : 285 = 81.80 : x
  2. Step 2: Convert to fraction form
    190/285 = 81.80/x
  3. Step 3: Cross multiply
    190x = 285 × 81.80
  4. Step 4: Simplify right side
    190x = 23,313
  5. Step 5: Solve for x
    x = 23,313/190
  6. Step 6: Final answer
    x = 122.70

Related Problems

Find fourth proportional to 95, 142.50 and 40.90
Half scale
Find fourth proportional to 380, 570 and 163.60
Double scale
Find fourth proportional to 191, 286.50 and 82.80
Similar ratio
Find fourth proportional to 285, 427.50 and 122.70
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.