Home / 92.88-128.40-80.70

Finding the Fourth Proportional to 92.88, 128.40 and 80.70

Calculator

Solution

The fourth proportional to 92.88, 128.40 and 80.70 is: 111.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.88 : 128.40 = 80.70 : x
  2. Step 2: Convert to fraction form
    92.88/128.40 = 80.70/x
  3. Step 3: Cross multiply
    92.88x = 128.40 × 80.70
  4. Step 4: Simplify right side
    92.88x = 10,361.88
  5. Step 5: Solve for x
    x = 10,361.88/92.88
  6. Step 6: Final answer
    x = 111.56

Related Problems

Find fourth proportional to 46.44, 64.20 and 40.35
Half scale
Find fourth proportional to 185.76, 256.80 and 161.40
Double scale
Find fourth proportional to 93.88, 129.78 and 81.70
Similar ratio
Find fourth proportional to 139.32, 192.60 and 121.05
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.