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Finding the Fourth Proportional to 1,378.51, 2,065.93 and 646.55

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Solution

The fourth proportional to 1,378.51, 2,065.93 and 646.55 is: 968.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.51 : 2,065.93 = 646.55 : x
  2. Step 2: Convert to fraction form
    1,378.51/2,065.93 = 646.55/x
  3. Step 3: Cross multiply
    1,378.51x = 2,065.93 × 646.55
  4. Step 4: Simplify right side
    1,378.51x = 1,335,727.04
  5. Step 5: Solve for x
    x = 1,335,727.04/1,378.51
  6. Step 6: Final answer
    x = 968.96

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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.