Home / 390.75-842.50

Finding the Third Proportional to 390.75 and 842.50

Calculator

Solution

The third proportional to 390.75 and 842.50 is: 1,816.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.75 : 842.50 = 842.50 : x
  2. Step 2: Convert to fraction form
    390.75/842.50 = 842.50/x
  3. Step 3: Cross multiply
    390.75x = 842.50 × 842.50
  4. Step 4: Simplify right side
    390.75x = 709,806.25
  5. Step 5: Solve for x
    x = 709,806.25/390.75
  6. Step 6: Final answer
    x = 1,816.52

Related Problems

Find third proportional to 195.38 and 421.25
Half scale
Find third proportional to 781.50 and 1,685
Double scale
Find third proportional to 393 and 847
Similar ratio
Find third proportional to 586.13 and 1,263.75
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.