Home / 158.21-218.31-103.05

Finding the Fourth Proportional to 158.21, 218.31 and 103.05

Calculator

Solution

The fourth proportional to 158.21, 218.31 and 103.05 is: 142.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.21 : 218.31 = 103.05 : x
  2. Step 2: Convert to fraction form
    158.21/218.31 = 103.05/x
  3. Step 3: Cross multiply
    158.21x = 218.31 × 103.05
  4. Step 4: Simplify right side
    158.21x = 22,496.85
  5. Step 5: Solve for x
    x = 22,496.85/158.21
  6. Step 6: Final answer
    x = 142.20

Related Problems

Find fourth proportional to 79.11, 109.16 and 51.53
Half scale
Find fourth proportional to 316.42, 436.62 and 206.10
Double scale
Find fourth proportional to 159.21, 219.69 and 104.05
Similar ratio
Find fourth proportional to 237.32, 327.47 and 154.58
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.