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Finding the Fourth Proportional to 897.99, 1,239.21 and 505

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Solution

The fourth proportional to 897.99, 1,239.21 and 505 is: 696.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    897.99 : 1,239.21 = 505 : x
  2. Step 2: Convert to fraction form
    897.99/1,239.21 = 505/x
  3. Step 3: Cross multiply
    897.99x = 1,239.21 × 505
  4. Step 4: Simplify right side
    897.99x = 625,801.05
  5. Step 5: Solve for x
    x = 625,801.05/897.99
  6. Step 6: Final answer
    x = 696.89

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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.