Home / 389.81-840.38

Finding the Third Proportional to 389.81 and 840.38

Calculator

Solution

The third proportional to 389.81 and 840.38 is: 1,811.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.81 : 840.38 = 840.38 : x
  2. Step 2: Convert to fraction form
    389.81/840.38 = 840.38/x
  3. Step 3: Cross multiply
    389.81x = 840.38 × 840.38
  4. Step 4: Simplify right side
    389.81x = 706,230.14
  5. Step 5: Solve for x
    x = 706,230.14/389.81
  6. Step 6: Final answer
    x = 1,811.72

Related Problems

Find third proportional to 194.91 and 420.19
Half scale
Find third proportional to 779.63 and 1,680.75
Double scale
Find third proportional to 392 and 845
Similar ratio
Find third proportional to 584.72 and 1,260.56
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.16) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.