Home / 153.31-211.56-87.80

Finding the Fourth Proportional to 153.31, 211.56 and 87.80

Calculator

Solution

The fourth proportional to 153.31, 211.56 and 87.80 is: 121.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.31 : 211.56 = 87.80 : x
  2. Step 2: Convert to fraction form
    153.31/211.56 = 87.80/x
  3. Step 3: Cross multiply
    153.31x = 211.56 × 87.80
  4. Step 4: Simplify right side
    153.31x = 18,574.53
  5. Step 5: Solve for x
    x = 18,574.53/153.31
  6. Step 6: Final answer
    x = 121.16

Related Problems

Find fourth proportional to 76.66, 105.78 and 43.90
Half scale
Find fourth proportional to 306.62, 423.11 and 175.60
Double scale
Find fourth proportional to 154.31, 212.93 and 88.80
Similar ratio
Find fourth proportional to 229.97, 317.33 and 131.70
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.