Home / 939.60-1,409.28-426.56

Finding the Fourth Proportional to 939.60, 1,409.28 and 426.56

Calculator

Solution

The fourth proportional to 939.60, 1,409.28 and 426.56 is: 639.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.60 : 1,409.28 = 426.56 : x
  2. Step 2: Convert to fraction form
    939.60/1,409.28 = 426.56/x
  3. Step 3: Cross multiply
    939.60x = 1,409.28 × 426.56
  4. Step 4: Simplify right side
    939.60x = 601,142.48
  5. Step 5: Solve for x
    x = 601,142.48/939.60
  6. Step 6: Final answer
    x = 639.79

Related Problems

Find fourth proportional to 469.80, 704.64 and 213.28
Half scale
Find fourth proportional to 1,879.20, 2,818.56 and 853.12
Double scale
Find fourth proportional to 940.60, 1,410.78 and 427.56
Similar ratio
Find fourth proportional to 1,409.40, 2,113.92 and 639.84
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.