Home / 231.89-319.98-128.39

Finding the Fourth Proportional to 231.89, 319.98 and 128.39

Calculator

Solution

The fourth proportional to 231.89, 319.98 and 128.39 is: 177.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.89 : 319.98 = 128.39 : x
  2. Step 2: Convert to fraction form
    231.89/319.98 = 128.39/x
  3. Step 3: Cross multiply
    231.89x = 319.98 × 128.39
  4. Step 4: Simplify right side
    231.89x = 41,082.23
  5. Step 5: Solve for x
    x = 41,082.23/231.89
  6. Step 6: Final answer
    x = 177.16

Related Problems

Find fourth proportional to 115.95, 159.99 and 64.20
Half scale
Find fourth proportional to 463.78, 639.96 and 256.78
Double scale
Find fourth proportional to 232.89, 321.36 and 129.39
Similar ratio
Find fourth proportional to 347.84, 479.97 and 192.59
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.