Home / 161.78-223.31-99.69

Finding the Fourth Proportional to 161.78, 223.31 and 99.69

Calculator

Solution

The fourth proportional to 161.78, 223.31 and 99.69 is: 137.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.78 : 223.31 = 99.69 : x
  2. Step 2: Convert to fraction form
    161.78/223.31 = 99.69/x
  3. Step 3: Cross multiply
    161.78x = 223.31 × 99.69
  4. Step 4: Simplify right side
    161.78x = 22,262.02
  5. Step 5: Solve for x
    x = 22,262.02/161.78
  6. Step 6: Final answer
    x = 137.61

Related Problems

Find fourth proportional to 80.89, 111.66 and 49.85
Half scale
Find fourth proportional to 323.55, 446.63 and 199.38
Double scale
Find fourth proportional to 162.78, 224.69 and 100.69
Similar ratio
Find fourth proportional to 242.66, 334.97 and 149.54
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.