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Finding the Fourth Proportional to 860.51, 1,187.57 and 640.10

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Solution

The fourth proportional to 860.51, 1,187.57 and 640.10 is: 883.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.51 : 1,187.57 = 640.10 : x
  2. Step 2: Convert to fraction form
    860.51/1,187.57 = 640.10/x
  3. Step 3: Cross multiply
    860.51x = 1,187.57 × 640.10
  4. Step 4: Simplify right side
    860.51x = 760,160.36
  5. Step 5: Solve for x
    x = 760,160.36/860.51
  6. Step 6: Final answer
    x = 883.38

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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.