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Finding the Fourth Proportional to 821.50, 1,131.48 and 646.54

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Solution

The fourth proportional to 821.50, 1,131.48 and 646.54 is: 890.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.50 : 1,131.48 = 646.54 : x
  2. Step 2: Convert to fraction form
    821.50/1,131.48 = 646.54/x
  3. Step 3: Cross multiply
    821.50x = 1,131.48 × 646.54
  4. Step 4: Simplify right side
    821.50x = 731,547.08
  5. Step 5: Solve for x
    x = 731,547.08/821.50
  6. Step 6: Final answer
    x = 890.50

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Double scale
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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.