Home / 994.29-1,381.12-978.40

Finding the Fourth Proportional to 994.29, 1,381.12 and 978.40

Calculator

Solution

The fourth proportional to 994.29, 1,381.12 and 978.40 is: 1,359.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    994.29 : 1,381.12 = 978.40 : x
  2. Step 2: Convert to fraction form
    994.29/1,381.12 = 978.40/x
  3. Step 3: Cross multiply
    994.29x = 1,381.12 × 978.40
  4. Step 4: Simplify right side
    994.29x = 1,351,287.86
  5. Step 5: Solve for x
    x = 1,351,287.86/994.29
  6. Step 6: Final answer
    x = 1,359.04

Related Problems

Find fourth proportional to 497.15, 690.56 and 489.20
Half scale
Find fourth proportional to 1,988.59, 2,762.24 and 1,956.80
Double scale
Find fourth proportional to 995.29, 1,382.51 and 979.40
Similar ratio
Find fourth proportional to 1,491.44, 2,071.68 and 1,467.60
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.