Home / 637.20-879.40-388.54

Finding the Fourth Proportional to 637.20, 879.40 and 388.54

Calculator

Solution

The fourth proportional to 637.20, 879.40 and 388.54 is: 536.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    637.20 : 879.40 = 388.54 : x
  2. Step 2: Convert to fraction form
    637.20/879.40 = 388.54/x
  3. Step 3: Cross multiply
    637.20x = 879.40 × 388.54
  4. Step 4: Simplify right side
    637.20x = 341,682.08
  5. Step 5: Solve for x
    x = 341,682.08/637.20
  6. Step 6: Final answer
    x = 536.22

Related Problems

Find fourth proportional to 318.60, 439.70 and 194.27
Half scale
Find fourth proportional to 1,274.40, 1,758.80 and 777.08
Double scale
Find fourth proportional to 638.20, 880.78 and 389.54
Similar ratio
Find fourth proportional to 955.80, 1,319.10 and 582.81
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.