What is the geometric mean of 3, 9, 27, 81, 243, 729, 2187?

Explanation

The numbers form a geometric progression and can be written as powers of 3: 3^1, 3^2, 3^3, 3^4, 3^5, 3^6, 3^7. Their product is 3^{1+2+3+4+5+6+7} = 3^{28}. The geometric mean of 7 terms is the 7th root of their product: (3^{28})^{\frac{1}{7}} = 3^4 = 81.

Related questions on Algebra

• If p + q + r = 0, then what is z^{\frac{p^2}{qr}} \times z^{\frac{q^2}{rp}} \times z^{\frac{r^2}{pq}} equal to ?
• What is the value of k for which (k^2 - 5k + 4)x^2 + (k^2 - 3k - 4)x + (k^2 - 4k) = 0 is an identity ?
• If \frac{a^2}{b^2 + c^2} = \frac{b^2}{c^2 + a^2} = \frac{c^2}{a^2 + b^2}, then what is the value of a^4 + b^4 + c^4 equal to ?
• If \frac{1}{x} = \frac{1}{p} + \frac{1}{q}, then what is \frac{pq}{p^2 - q^2}\left(\frac{x + p}{x - p} - \frac{x + q}{x - q}\right) equa...
• If (x - 5) is the HCF of x^2 - x - p and x^2 - qx - 10, then what is the value of (p + q) ?