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Finding the Fourth Proportional to 915.90, 1,265.94 and 770.64

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Solution

The fourth proportional to 915.90, 1,265.94 and 770.64 is: 1,065.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    915.90 : 1,265.94 = 770.64 : x
  2. Step 2: Convert to fraction form
    915.90/1,265.94 = 770.64/x
  3. Step 3: Cross multiply
    915.90x = 1,265.94 × 770.64
  4. Step 4: Simplify right side
    915.90x = 975,584.00
  5. Step 5: Solve for x
    x = 975,584.00/915.90
  6. Step 6: Final answer
    x = 1,065.16

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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.