Home / 618.28-853.62-385.72

Finding the Fourth Proportional to 618.28, 853.62 and 385.72

Calculator

Solution

The fourth proportional to 618.28, 853.62 and 385.72 is: 532.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.28 : 853.62 = 385.72 : x
  2. Step 2: Convert to fraction form
    618.28/853.62 = 385.72/x
  3. Step 3: Cross multiply
    618.28x = 853.62 × 385.72
  4. Step 4: Simplify right side
    618.28x = 329,258.31
  5. Step 5: Solve for x
    x = 329,258.31/618.28
  6. Step 6: Final answer
    x = 532.54

Related Problems

Find fourth proportional to 309.14, 426.81 and 192.86
Half scale
Find fourth proportional to 1,236.56, 1,707.24 and 771.44
Double scale
Find fourth proportional to 619.28, 855 and 386.72
Similar ratio
Find fourth proportional to 927.42, 1,280.43 and 578.58
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.