Home / 651.88-978.04-213.15

Finding the Fourth Proportional to 651.88, 978.04 and 213.15

Calculator

Solution

The fourth proportional to 651.88, 978.04 and 213.15 is: 319.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    651.88 : 978.04 = 213.15 : x
  2. Step 2: Convert to fraction form
    651.88/978.04 = 213.15/x
  3. Step 3: Cross multiply
    651.88x = 978.04 × 213.15
  4. Step 4: Simplify right side
    651.88x = 208,470.19
  5. Step 5: Solve for x
    x = 208,470.19/651.88
  6. Step 6: Final answer
    x = 319.80

Related Problems

Find fourth proportional to 325.94, 489.02 and 106.58
Half scale
Find fourth proportional to 1,303.76, 1,956.08 and 426.30
Double scale
Find fourth proportional to 652.88, 979.54 and 214.15
Similar ratio
Find fourth proportional to 977.82, 1,467.06 and 319.73
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.