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Finding the Fourth Proportional to 1,386.15, 2,080.08 and 645.63

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Solution

The fourth proportional to 1,386.15, 2,080.08 and 645.63 is: 968.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.15 : 2,080.08 = 645.63 : x
  2. Step 2: Convert to fraction form
    1,386.15/2,080.08 = 645.63/x
  3. Step 3: Cross multiply
    1,386.15x = 2,080.08 × 645.63
  4. Step 4: Simplify right side
    1,386.15x = 1,342,962.05
  5. Step 5: Solve for x
    x = 1,342,962.05/1,386.15
  6. Step 6: Final answer
    x = 968.84

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1.5x scale

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.