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Finding the Fourth Proportional to 870.75, 1,306.53 and 438.21

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Solution

The fourth proportional to 870.75, 1,306.53 and 438.21 is: 657.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.75 : 1,306.53 = 438.21 : x
  2. Step 2: Convert to fraction form
    870.75/1,306.53 = 438.21/x
  3. Step 3: Cross multiply
    870.75x = 1,306.53 × 438.21
  4. Step 4: Simplify right side
    870.75x = 572,534.51
  5. Step 5: Solve for x
    x = 572,534.51/870.75
  6. Step 6: Final answer
    x = 657.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.