geometric

  1. J

    Geometric Distribution Probability

    According to the law of conditional probability, P(A∩B) = P(A|B)P(B) so for a geometric distribution, P(X>k+j|X>k) = P(X>k+j∩X>k)/P(X>k) P(X>k+j∩X>k) = P(X>k+j) because if X>k+j, then X>k (because j is a positive integer) <--- Why is this so, why X>k+j, then X>k?
  2. J

    Geometric Distribution

    Hi, wondering if anyone could help me out with the question below! Let X have a geometric distribution. Show thatP(X >k+j|X >k)=P(X >j), where k and j are nonnegative integers. Note: We some-times say that in this situation there has been loss ofmemory.
  3. M

    question about finding a term in a geometric sequence

    A problem asks to find S6 for a geometric sequence starting with 4 with a common ratio 2. The answer given is: 252 I thought use the equation: an = a1 * r(n-1) so: an = 4 * 2(6-1) .....but this appears wrong according to the answer. Can someone help? (Headbang)
  4. R

    Geometric Proofs Disappearing

    Why are more and more high schools across the USA doing away with direct and indirect geometric proofs? Why do students struggle so much with proofs?
  5. M

    Geometric Sequence

    find the 1st term of geometric sequence whose 4th term and 7th term is 108 and 2,960
  6. S

    Geometric Series Cos

    The question I'm looking at is: \sum_{n=1}^\infty \frac{cos\left(n\pi\right)}{2^n} Find if converge or diverge and if converge find the sum. The only things I have learned so far about series is the nth term test and geometric series. So my first attempt is to is if it diverges using the nth...
  7. Y

    Geometric Gradient

    Hi! I have a problem about gradient with devaluation. A factory imports 80 tons of raw material paying it at the beginning of each month at US\$200 a ton. The peso depreciates at the rate of 2.5 % a month against the dollar. if the current exchange rate is US\$1 = \$400pesos, find the total...
  8. Jason76

    Geometric Series Divergence - # 2

    Why does this diverge? How to go about working with this one. Is it a geometric series? It doesn't look like one.
  9. Jason76

    Geometric Series Divergence

    Why is this divergent? Series with n = 1: \dfrac{7n}{(-6)^{n-1}} (\dfrac{7}{1}})\dfrac{7n}{(-6)^{n-1}} ?? r = -\dfrac{7}{6} |r| = \dfrac{7}{6} \geq 1 a = 7 - can be proven by plugging in 1 into the series variable n. Wait I see the error now. Originally I wasn't taking the absolute...
  10. D

    Diminished Radix Complement (geometric pattern)

    So I'm reading about Radix Complements on Wikipedia, and there is a geometric pattern used to prove the following statement: The radix complement is most easily obtained by adding 1 to the diminished radix complement, which is (bn-1)-y. Since bn-1 is the digit b-1 repeated n times because bn-1...
  11. C

    Geometric Sequence

    A geometric sequence has an initial value of 3 and a common ratio of 2. Write a function to represent this sequence.
  12. D

    Variance of geometric mean

    Please help me out !! Suppose Y1, Y2, . . . , Yn is a random sample from the uniform pdf over [0, 1]. find the variance of the geometric mean when n = 2 and more ( a generalized solution).
  13. P

    Need help with finding limit of a finite Geometric sequence

    The sequence is stated as such: √3, 1, √3/3, .... If someone can help me out, that would be great!
  14. J

    Geometric growth and decay

    I need help with this question....If someone can show me the steps on how to it that would be awesome! A small square picture measures 3 1/2 inches by 3 1/2 inches. A photocopier is set to produce copies that are an enlargement of the original such that both the length and width are increased...
  15. sakonpure6

    Geometric description

    Hello, How would you geometrically describe a subset of W = \{(a-2b,a,a+b)|a,b \in R\} = span \{(1,1,1),(-2,0,1)\} ? Or any span? Thank you. -Sakon
  16. T

    Need a little bit of help with this geometric sequence.

    I am having trouble figuring out what r equals in an=a1rn-1 with the given information. a2 = 7, a4 = 1575. After I get r, it should not be to difficult to get a1 and then the actual formula for any given term. Thank you!
  17. B

    addition of geometric progression

    how the addition of geometric series gives 2 and product gives 40
  18. A

    Geometric interpretation of complex numbers

    Set B is defined as B = {z| |z11|=|i| }. The answer is the unit circle. Why? And what about B = {z| z11=i }
  19. A

    Geometric interpretation of complex numbers

    Set B is defined as B = {z| |z11|=|i| }. The answer is the unit circle. Why? And what about B = {z| z11=i }
  20. Jason76

    Geometric Series - Converge or Diverge - # 12

    Converge or diverge? \displaystyle\sum_{n=0}^{\infty} \dfrac{2^{n+1}}{5^{n}} What would be the strategy in finding r?