Home / 75.78-104.28-68.88

Finding the Fourth Proportional to 75.78, 104.28 and 68.88

Calculator

Solution

The fourth proportional to 75.78, 104.28 and 68.88 is: 94.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.78 : 104.28 = 68.88 : x
  2. Step 2: Convert to fraction form
    75.78/104.28 = 68.88/x
  3. Step 3: Cross multiply
    75.78x = 104.28 × 68.88
  4. Step 4: Simplify right side
    75.78x = 7,182.81
  5. Step 5: Solve for x
    x = 7,182.81/75.78
  6. Step 6: Final answer
    x = 94.78

Related Problems

Find fourth proportional to 37.89, 52.14 and 34.44
Half scale
Find fourth proportional to 151.56, 208.56 and 137.76
Double scale
Find fourth proportional to 76.78, 105.66 and 69.88
Similar ratio
Find fourth proportional to 113.67, 156.42 and 103.32
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.