Home / 393.26-540.47-305.78

Finding the Fourth Proportional to 393.26, 540.47 and 305.78

Calculator

Solution

The fourth proportional to 393.26, 540.47 and 305.78 is: 420.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.26 : 540.47 = 305.78 : x
  2. Step 2: Convert to fraction form
    393.26/540.47 = 305.78/x
  3. Step 3: Cross multiply
    393.26x = 540.47 × 305.78
  4. Step 4: Simplify right side
    393.26x = 165,262.98
  5. Step 5: Solve for x
    x = 165,262.98/393.26
  6. Step 6: Final answer
    x = 420.24

Related Problems

Find fourth proportional to 196.63, 270.24 and 152.89
Half scale
Find fourth proportional to 786.51, 1,080.95 and 611.55
Double scale
Find fourth proportional to 394.26, 541.85 and 306.78
Similar ratio
Find fourth proportional to 589.88, 810.71 and 458.66
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.