Home / 386.50-579.75-130

Finding the Fourth Proportional to 386.50, 579.75 and 130

Calculator

Solution

The fourth proportional to 386.50, 579.75 and 130 is: 195

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.50 : 579.75 = 130 : x
  2. Step 2: Convert to fraction form
    386.50/579.75 = 130/x
  3. Step 3: Cross multiply
    386.50x = 579.75 × 130
  4. Step 4: Simplify right side
    386.50x = 75,367.50
  5. Step 5: Solve for x
    x = 75,367.50/386.50
  6. Step 6: Final answer
    x = 195

Related Problems

Find fourth proportional to 193.25, 289.88 and 65
Half scale
Find fourth proportional to 773, 1,159.50 and 260
Double scale
Find fourth proportional to 387.50, 581.25 and 131
Similar ratio
Find fourth proportional to 579.75, 869.63 and 195
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.