Home / 121.65-167.78-80.21

Finding the Fourth Proportional to 121.65, 167.78 and 80.21

Calculator

Solution

The fourth proportional to 121.65, 167.78 and 80.21 is: 110.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.65 : 167.78 = 80.21 : x
  2. Step 2: Convert to fraction form
    121.65/167.78 = 80.21/x
  3. Step 3: Cross multiply
    121.65x = 167.78 × 80.21
  4. Step 4: Simplify right side
    121.65x = 13,456.39
  5. Step 5: Solve for x
    x = 13,456.39/121.65
  6. Step 6: Final answer
    x = 110.62

Related Problems

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.