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Finding the Fourth Proportional to 840.70, 1,158.65 and 644.68

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Solution

The fourth proportional to 840.70, 1,158.65 and 644.68 is: 888.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.70 : 1,158.65 = 644.68 : x
  2. Step 2: Convert to fraction form
    840.70/1,158.65 = 644.68/x
  3. Step 3: Cross multiply
    840.70x = 1,158.65 × 644.68
  4. Step 4: Simplify right side
    840.70x = 746,952.69
  5. Step 5: Solve for x
    x = 746,952.69/840.70
  6. Step 6: Final answer
    x = 888.49

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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.