Home / 186.81-257.88-128.89

Finding the Fourth Proportional to 186.81, 257.88 and 128.89

Calculator

Solution

The fourth proportional to 186.81, 257.88 and 128.89 is: 177.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    186.81 : 257.88 = 128.89 : x
  2. Step 2: Convert to fraction form
    186.81/257.88 = 128.89/x
  3. Step 3: Cross multiply
    186.81x = 257.88 × 128.89
  4. Step 4: Simplify right side
    186.81x = 33,238.15
  5. Step 5: Solve for x
    x = 33,238.15/186.81
  6. Step 6: Final answer
    x = 177.92

Related Problems

Find fourth proportional to 93.41, 128.94 and 64.45
Half scale
Find fourth proportional to 373.62, 515.76 and 257.78
Double scale
Find fourth proportional to 187.81, 259.26 and 129.89
Similar ratio
Find fourth proportional to 280.22, 386.82 and 193.34
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.