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Finding the Fourth Proportional to 783.90, 1,079.32 and 665.63

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Solution

The fourth proportional to 783.90, 1,079.32 and 665.63 is: 916.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.90 : 1,079.32 = 665.63 : x
  2. Step 2: Convert to fraction form
    783.90/1,079.32 = 665.63/x
  3. Step 3: Cross multiply
    783.90x = 1,079.32 × 665.63
  4. Step 4: Simplify right side
    783.90x = 718,420.71
  5. Step 5: Solve for x
    x = 718,420.71/783.90
  6. Step 6: Final answer
    x = 916.47

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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.