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Finding the Fourth Proportional to 957.96, 1,321.75 and 643.80

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Solution

The fourth proportional to 957.96, 1,321.75 and 643.80 is: 888.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    957.96 : 1,321.75 = 643.80 : x
  2. Step 2: Convert to fraction form
    957.96/1,321.75 = 643.80/x
  3. Step 3: Cross multiply
    957.96x = 1,321.75 × 643.80
  4. Step 4: Simplify right side
    957.96x = 850,942.65
  5. Step 5: Solve for x
    x = 850,942.65/957.96
  6. Step 6: Final answer
    x = 888.29

Related Problems

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Half scale
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Double scale
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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.