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Finding the Fourth Proportional to 713.71, 985.47 and 643.49

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Solution

The fourth proportional to 713.71, 985.47 and 643.49 is: 888.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    713.71 : 985.47 = 643.49 : x
  2. Step 2: Convert to fraction form
    713.71/985.47 = 643.49/x
  3. Step 3: Cross multiply
    713.71x = 985.47 × 643.49
  4. Step 4: Simplify right side
    713.71x = 634,140.09
  5. Step 5: Solve for x
    x = 634,140.09/713.71
  6. Step 6: Final answer
    x = 888.51

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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.