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Finding the Fourth Proportional to 975.38, 1,344.81 and 643.28

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Solution

The fourth proportional to 975.38, 1,344.81 and 643.28 is: 886.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    975.38 : 1,344.81 = 643.28 : x
  2. Step 2: Convert to fraction form
    975.38/1,344.81 = 643.28/x
  3. Step 3: Cross multiply
    975.38x = 1,344.81 × 643.28
  4. Step 4: Simplify right side
    975.38x = 865,089.38
  5. Step 5: Solve for x
    x = 865,089.38/975.38
  6. Step 6: Final answer
    x = 886.93

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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.