Home / 788.85-1,088.34-489.78

Finding the Fourth Proportional to 788.85, 1,088.34 and 489.78

Calculator

Solution

The fourth proportional to 788.85, 1,088.34 and 489.78 is: 675.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    788.85 : 1,088.34 = 489.78 : x
  2. Step 2: Convert to fraction form
    788.85/1,088.34 = 489.78/x
  3. Step 3: Cross multiply
    788.85x = 1,088.34 × 489.78
  4. Step 4: Simplify right side
    788.85x = 533,047.17
  5. Step 5: Solve for x
    x = 533,047.17/788.85
  6. Step 6: Final answer
    x = 675.73

Related Problems

Find fourth proportional to 394.43, 544.17 and 244.89
Half scale
Find fourth proportional to 1,577.70, 2,176.68 and 979.56
Double scale
Find fourth proportional to 789.85, 1,089.72 and 490.78
Similar ratio
Find fourth proportional to 1,183.28, 1,632.51 and 734.67
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.