Home / 55.49-83.21-21.28

Finding the Fourth Proportional to 55.49, 83.21 and 21.28

Calculator

Solution

The fourth proportional to 55.49, 83.21 and 21.28 is: 31.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.49 : 83.21 = 21.28 : x
  2. Step 2: Convert to fraction form
    55.49/83.21 = 21.28/x
  3. Step 3: Cross multiply
    55.49x = 83.21 × 21.28
  4. Step 4: Simplify right side
    55.49x = 1,770.45
  5. Step 5: Solve for x
    x = 1,770.45/55.49
  6. Step 6: Final answer
    x = 31.91

Related Problems

Find fourth proportional to 27.74, 41.60 and 10.64
Half scale
Find fourth proportional to 110.98, 166.42 and 42.56
Double scale
Find fourth proportional to 56.49, 84.71 and 22.28
Similar ratio
Find fourth proportional to 83.23, 124.81 and 31.92
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.