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Finding the Fourth Proportional to 857.20, 1,284.88 and 491.20

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Solution

The fourth proportional to 857.20, 1,284.88 and 491.20 is: 736.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.20 : 1,284.88 = 491.20 : x
  2. Step 2: Convert to fraction form
    857.20/1,284.88 = 491.20/x
  3. Step 3: Cross multiply
    857.20x = 1,284.88 × 491.20
  4. Step 4: Simplify right side
    857.20x = 631,133.06
  5. Step 5: Solve for x
    x = 631,133.06/857.20
  6. Step 6: Final answer
    x = 736.27

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Double scale
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1.5x scale

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.