Home / 653.80-902.26-391.78

Finding the Fourth Proportional to 653.80, 902.26 and 391.78

Calculator

Solution

The fourth proportional to 653.80, 902.26 and 391.78 is: 540.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.80 : 902.26 = 391.78 : x
  2. Step 2: Convert to fraction form
    653.80/902.26 = 391.78/x
  3. Step 3: Cross multiply
    653.80x = 902.26 × 391.78
  4. Step 4: Simplify right side
    653.80x = 353,487.42
  5. Step 5: Solve for x
    x = 353,487.42/653.80
  6. Step 6: Final answer
    x = 540.67

Related Problems

Find fourth proportional to 326.90, 451.13 and 195.89
Half scale
Find fourth proportional to 1,307.60, 1,804.52 and 783.56
Double scale
Find fourth proportional to 654.80, 903.64 and 392.78
Similar ratio
Find fourth proportional to 980.70, 1,353.39 and 587.67
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.