Home / 157.80-217.86-120.85

Finding the Fourth Proportional to 157.80, 217.86 and 120.85

Calculator

Solution

The fourth proportional to 157.80, 217.86 and 120.85 is: 166.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.80 : 217.86 = 120.85 : x
  2. Step 2: Convert to fraction form
    157.80/217.86 = 120.85/x
  3. Step 3: Cross multiply
    157.80x = 217.86 × 120.85
  4. Step 4: Simplify right side
    157.80x = 26,327.38
  5. Step 5: Solve for x
    x = 26,327.38/157.80
  6. Step 6: Final answer
    x = 166.84

Related Problems

Find fourth proportional to 78.90, 108.93 and 60.42
Half scale
Find fourth proportional to 315.61, 435.71 and 241.70
Double scale
Find fourth proportional to 158.80, 219.24 and 121.85
Similar ratio
Find fourth proportional to 236.71, 326.78 and 181.27
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.