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Finding the Fourth Proportional to 643.30, 888.13 and 422.63

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Solution

The fourth proportional to 643.30, 888.13 and 422.63 is: 583.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.30 : 888.13 = 422.63 : x
  2. Step 2: Convert to fraction form
    643.30/888.13 = 422.63/x
  3. Step 3: Cross multiply
    643.30x = 888.13 × 422.63
  4. Step 4: Simplify right side
    643.30x = 375,350.38
  5. Step 5: Solve for x
    x = 375,350.38/643.30
  6. Step 6: Final answer
    x = 583.48

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Double scale
Find fourth proportional to 644.30, 889.51 and 423.63
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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.