Home / 60.78-91.20-30.42

Finding the Fourth Proportional to 60.78, 91.20 and 30.42

Calculator

Solution

The fourth proportional to 60.78, 91.20 and 30.42 is: 45.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    60.78 : 91.20 = 30.42 : x
  2. Step 2: Convert to fraction form
    60.78/91.20 = 30.42/x
  3. Step 3: Cross multiply
    60.78x = 91.20 × 30.42
  4. Step 4: Simplify right side
    60.78x = 2,774.30
  5. Step 5: Solve for x
    x = 2,774.30/60.78
  6. Step 6: Final answer
    x = 45.65

Related Problems

Find fourth proportional to 30.39, 45.60 and 15.21
Half scale
Find fourth proportional to 121.56, 182.40 and 60.84
Double scale
Find fourth proportional to 61.78, 92.70 and 31.42
Similar ratio
Find fourth proportional to 91.17, 136.80 and 45.63
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.