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Finding the Fourth Proportional to 618.75, 853.77 and 397.89

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Solution

The fourth proportional to 618.75, 853.77 and 397.89 is: 549.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.75 : 853.77 = 397.89 : x
  2. Step 2: Convert to fraction form
    618.75/853.77 = 397.89/x
  3. Step 3: Cross multiply
    618.75x = 853.77 × 397.89
  4. Step 4: Simplify right side
    618.75x = 339,706.55
  5. Step 5: Solve for x
    x = 339,706.55/618.75
  6. Step 6: Final answer
    x = 549.02

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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.