Home / 192.40-288.72-138.40

Finding the Fourth Proportional to 192.40, 288.72 and 138.40

Calculator

Solution

The fourth proportional to 192.40, 288.72 and 138.40 is: 207.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    192.40 : 288.72 = 138.40 : x
  2. Step 2: Convert to fraction form
    192.40/288.72 = 138.40/x
  3. Step 3: Cross multiply
    192.40x = 288.72 × 138.40
  4. Step 4: Simplify right side
    192.40x = 39,958.85
  5. Step 5: Solve for x
    x = 39,958.85/192.40
  6. Step 6: Final answer
    x = 207.69

Related Problems

Find fourth proportional to 96.20, 144.36 and 69.20
Half scale
Find fourth proportional to 384.80, 577.44 and 276.80
Double scale
Find fourth proportional to 193.40, 290.22 and 139.40
Similar ratio
Find fourth proportional to 288.60, 433.08 and 207.60
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.