Math Problem Statement

2 between 2 and 54 using geometric means formula

Solution

To find the two numbers between 2 and 54 using geometric means, we are essentially looking for numbers that form a geometric sequence between 2 and 54.

In a geometric sequence, the ratio between consecutive terms is constant. Let's denote the four numbers in the geometric sequence as: a1=2,a2=x1,a3=x2,a4=54a_1 = 2, \, a_2 = x_1, \, a_3 = x_2, \, a_4 = 54 where x1x_1 and x2x_2 are the two numbers we need to find.

The formula for the nn-th term of a geometric sequence is given by: an=a1rn1a_n = a_1 \cdot r^{n-1} where rr is the common ratio, and nn is the position of the term in the sequence.

Step 1: Find the common ratio

Since there are four terms, a4=54a_4 = 54 and a1=2a_1 = 2, the common ratio rr is found as: 54=2r354 = 2 \cdot r^3 Solve for rr: r3=542=27r^3 = \frac{54}{2} = 27 r=273=3r = \sqrt[3]{27} = 3

Step 2: Find the two numbers

Now that we know the common ratio r=3r = 3, we can find the second and third terms: x1=a1r=23=6x_1 = a_1 \cdot r = 2 \cdot 3 = 6 x2=a1r2=232=29=18x_2 = a_1 \cdot r^2 = 2 \cdot 3^2 = 2 \cdot 9 = 18

Final Result:

The two numbers between 2 and 54 in geometric sequence are 6 and 18.

Would you like more details on how this formula works or any other aspects? Here are five related questions to deepen your understanding:

  1. How is the geometric sequence different from an arithmetic sequence?
  2. Can you find the geometric mean of two other numbers using this method?
  3. What if there were more terms between 2 and 54? How would that change the calculation?
  4. How does the concept of a geometric sequence apply in real-world scenarios, such as population growth?
  5. What happens if the first and last numbers are negative? Would the geometric mean still work?

Tip: In a geometric sequence, the ratio between consecutive terms remains constant, whereas in an arithmetic sequence, the difference between consecutive terms is constant.

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Math Problem Analysis

Mathematical Concepts

Geometric Sequence
Geometric Mean
Algebra

Formulas

nth term of a geometric sequence: a_n = a_1 * r^(n-1)

Theorems

Properties of Geometric Sequences

Suitable Grade Level

Grades 9-10