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Finding the Fourth Proportional to 786.40, 1,172.73 and 689.35

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Solution

The fourth proportional to 786.40, 1,172.73 and 689.35 is: 1,028.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.40 : 1,172.73 = 689.35 : x
  2. Step 2: Convert to fraction form
    786.40/1,172.73 = 689.35/x
  3. Step 3: Cross multiply
    786.40x = 1,172.73 × 689.35
  4. Step 4: Simplify right side
    786.40x = 808,421.43
  5. Step 5: Solve for x
    x = 808,421.43/786.40
  6. Step 6: Final answer
    x = 1,028.00

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.