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Finding the Fourth Proportional to 817.91, 1,128.85 and 486.51

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Solution

The fourth proportional to 817.91, 1,128.85 and 486.51 is: 671.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.91 : 1,128.85 = 486.51 : x
  2. Step 2: Convert to fraction form
    817.91/1,128.85 = 486.51/x
  3. Step 3: Cross multiply
    817.91x = 1,128.85 × 486.51
  4. Step 4: Simplify right side
    817.91x = 549,196.81
  5. Step 5: Solve for x
    x = 549,196.81/817.91
  6. Step 6: Final answer
    x = 671.46

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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.