Home / 931.50-1,285.74-621

Finding the Fourth Proportional to 931.50, 1,285.74 and 621

Calculator

Solution

The fourth proportional to 931.50, 1,285.74 and 621 is: 857.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    931.50 : 1,285.74 = 621 : x
  2. Step 2: Convert to fraction form
    931.50/1,285.74 = 621/x
  3. Step 3: Cross multiply
    931.50x = 1,285.74 × 621
  4. Step 4: Simplify right side
    931.50x = 798,444.54
  5. Step 5: Solve for x
    x = 798,444.54/931.50
  6. Step 6: Final answer
    x = 857.16

Related Problems

Find fourth proportional to 465.75, 642.87 and 310.50
Half scale
Find fourth proportional to 1,863, 2,571.48 and 1,242
Double scale
Find fourth proportional to 932.50, 1,287.12 and 622
Similar ratio
Find fourth proportional to 1,397.25, 1,928.61 and 931.50
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.