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Finding the Fourth Proportional to 645.38, 889.65 and 551.42

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Solution

The fourth proportional to 645.38, 889.65 and 551.42 is: 760.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.38 : 889.65 = 551.42 : x
  2. Step 2: Convert to fraction form
    645.38/889.65 = 551.42/x
  3. Step 3: Cross multiply
    645.38x = 889.65 × 551.42
  4. Step 4: Simplify right side
    645.38x = 490,570.80
  5. Step 5: Solve for x
    x = 490,570.80/645.38
  6. Step 6: Final answer
    x = 760.13

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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.