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Finding the Fourth Proportional to 718.30, 991.27 and 438.54

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Solution

The fourth proportional to 718.30, 991.27 and 438.54 is: 605.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.30 : 991.27 = 438.54 : x
  2. Step 2: Convert to fraction form
    718.30/991.27 = 438.54/x
  3. Step 3: Cross multiply
    718.30x = 991.27 × 438.54
  4. Step 4: Simplify right side
    718.30x = 434,711.55
  5. Step 5: Solve for x
    x = 434,711.55/718.30
  6. Step 6: Final answer
    x = 605.19

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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.