Home / 187.21-280.85-142.12

Finding the Fourth Proportional to 187.21, 280.85 and 142.12

Calculator

Solution

The fourth proportional to 187.21, 280.85 and 142.12 is: 213.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.21 : 280.85 = 142.12 : x
  2. Step 2: Convert to fraction form
    187.21/280.85 = 142.12/x
  3. Step 3: Cross multiply
    187.21x = 280.85 × 142.12
  4. Step 4: Simplify right side
    187.21x = 39,914.40
  5. Step 5: Solve for x
    x = 39,914.40/187.21
  6. Step 6: Final answer
    x = 213.21

Related Problems

Find fourth proportional to 93.61, 140.43 and 71.06
Half scale
Find fourth proportional to 374.42, 561.70 and 284.24
Double scale
Find fourth proportional to 188.21, 282.35 and 143.12
Similar ratio
Find fourth proportional to 280.82, 421.28 and 213.18
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.