Home / 82.95-123.80-81.60

Finding the Fourth Proportional to 82.95, 123.80 and 81.60

Calculator

Solution

The fourth proportional to 82.95, 123.80 and 81.60 is: 121.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.95 : 123.80 = 81.60 : x
  2. Step 2: Convert to fraction form
    82.95/123.80 = 81.60/x
  3. Step 3: Cross multiply
    82.95x = 123.80 × 81.60
  4. Step 4: Simplify right side
    82.95x = 10,102.08
  5. Step 5: Solve for x
    x = 10,102.08/82.95
  6. Step 6: Final answer
    x = 121.79

Related Problems

Find fourth proportional to 41.48, 61.90 and 40.80
Half scale
Find fourth proportional to 165.90, 247.60 and 163.20
Double scale
Find fourth proportional to 83.95, 125.29 and 82.60
Similar ratio
Find fourth proportional to 124.43, 185.70 and 122.40
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.