Home / 618.79-853.97-397.60

Finding the Fourth Proportional to 618.79, 853.97 and 397.60

Calculator

Solution

The fourth proportional to 618.79, 853.97 and 397.60 is: 548.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.79 : 853.97 = 397.60 : x
  2. Step 2: Convert to fraction form
    618.79/853.97 = 397.60/x
  3. Step 3: Cross multiply
    618.79x = 853.97 × 397.60
  4. Step 4: Simplify right side
    618.79x = 339,538.47
  5. Step 5: Solve for x
    x = 339,538.47/618.79
  6. Step 6: Final answer
    x = 548.71

Related Problems

Find fourth proportional to 309.40, 426.99 and 198.80
Half scale
Find fourth proportional to 1,237.58, 1,707.94 and 795.20
Double scale
Find fourth proportional to 619.79, 855.35 and 398.60
Similar ratio
Find fourth proportional to 928.19, 1,280.96 and 596.40
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.