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Finding the Fourth Proportional to 790.65, 1,090.78 and 495.40

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Solution

The fourth proportional to 790.65, 1,090.78 and 495.40 is: 683.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.65 : 1,090.78 = 495.40 : x
  2. Step 2: Convert to fraction form
    790.65/1,090.78 = 495.40/x
  3. Step 3: Cross multiply
    790.65x = 1,090.78 × 495.40
  4. Step 4: Simplify right side
    790.65x = 540,372.41
  5. Step 5: Solve for x
    x = 540,372.41/790.65
  6. Step 6: Final answer
    x = 683.45

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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.