Home / 189.78-284.49-87

Finding the Fourth Proportional to 189.78, 284.49 and 87

Calculator

Solution

The fourth proportional to 189.78, 284.49 and 87 is: 130.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    189.78 : 284.49 = 87 : x
  2. Step 2: Convert to fraction form
    189.78/284.49 = 87/x
  3. Step 3: Cross multiply
    189.78x = 284.49 × 87
  4. Step 4: Simplify right side
    189.78x = 24,750.63
  5. Step 5: Solve for x
    x = 24,750.63/189.78
  6. Step 6: Final answer
    x = 130.42

Related Problems

Find fourth proportional to 94.89, 142.25 and 43.50
Half scale
Find fourth proportional to 379.56, 568.98 and 174
Double scale
Find fourth proportional to 190.78, 285.99 and 88
Similar ratio
Find fourth proportional to 284.67, 426.74 and 130.50
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.