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Finding the Fourth Proportional to 908.25, 1,253.40 and 643.16

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Solution

The fourth proportional to 908.25, 1,253.40 and 643.16 is: 887.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    908.25 : 1,253.40 = 643.16 : x
  2. Step 2: Convert to fraction form
    908.25/1,253.40 = 643.16/x
  3. Step 3: Cross multiply
    908.25x = 1,253.40 × 643.16
  4. Step 4: Simplify right side
    908.25x = 806,130.48
  5. Step 5: Solve for x
    x = 806,130.48/908.25
  6. Step 6: Final answer
    x = 887.56

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Double scale
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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.