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Finding the Fourth Proportional to 720.19, 991.28 and 637.63

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Solution

The fourth proportional to 720.19, 991.28 and 637.63 is: 877.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.19 : 991.28 = 637.63 : x
  2. Step 2: Convert to fraction form
    720.19/991.28 = 637.63/x
  3. Step 3: Cross multiply
    720.19x = 991.28 × 637.63
  4. Step 4: Simplify right side
    720.19x = 632,066.68
  5. Step 5: Solve for x
    x = 632,066.68/720.19
  6. Step 6: Final answer
    x = 877.64

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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.