Recent content by EdmureTully

  1. E

    When do we use the average range instead of the average moving range?

    Homework Statement Homework Equations =̿+2̅, =̿−2 =4̅, =3̅ The Attempt at a Solution From what I gather, we can use the sample range, which is the max minus the min, or the average moving range which is the sum of the preceding value minus the current value divided by the...
  2. E

    Calculating Sales Change with Price Elasticity of Demand

    I don't have that formula. It's not even a homework problem. I just want to know how to determine the new quantity.
  3. E

    Calculating Sales Change with Price Elasticity of Demand

    Homework Statement Given a price elasticity of 1.6 and an initial sales number of 10000 what would be the sales number if price went from 4.99 to 10.00? Homework Equations Price Elasticity of Demand = % Change in Quantity Demanded / % Change in Price The Attempt at a Solution...
  4. E

    Calculating Standard Deviation Homework

    Ok, thanks. One last thing, do I have to divide by n-1 or just n?
  5. E

    Calculating Standard Deviation Homework

    Homework Statement I have to calculate the standard deviation Homework Equations http://0.tqn.com/d/statistics/1/0/M/-/-/-/standarddev.GIF The Attempt at a Solution 0.64 0.4096 2.06 4.2436 0.16 0.0256 3.24 10.4976 1.74 3.0276 1.06 1.1236 4.04 16.3216 1.56 2.4336 1.3 1.69...
  6. E

    Undergrad How do you estimate the sample size of a population given that there i

    i need the formulas and the steps i know how to use the confidence interval equation after that it gets dark $$\frac{N*Var(x)}{(N-1)B^{2}/k^{2} + Var(x)}$$ break down the above equations into many steps and formulas
  7. E

    Why do multi-valued attributes imply 1:M relationships?

    I don't understand why they do, because it doesn't necessarily mean that one tuple is tied to several instances of the multi-valued attributes from another table.
  8. E

    Standard normal distribution problem

    Homework Statement (Page 222 number 5) A highway department has enough salt to handle a total of 80 inches of snowfall. Suppose the daily amount of snow has a mean of 1.5 inches and a standard deviation of .3 inches. Approximate the probability that the salt on hand will suffice for...
  9. E

    MySQL: Using Aliases & Old Names

    If you rename an attribute or a relation with the keyword AS in MYSQL can you use the alias created outside the query where you renamed the attribute, also can you use the old name?
  10. E

    Graduate Are random variables based on the same pmf or pdf always independent?

    How do you verify their independence then? Any quick and easy way? Any obvious cases?
  11. E

    Graduate Are random variables based on the same pmf or pdf always independent?

    Are they always independent from each other so that you can multiply their E[X] together to form another E[X] with the same distribution and pmf or pdf?
  12. E

    What's the expected value of this problem (random variable)?

    The pattern I see leads me to believe it's 0.
  13. E

    What's the expected value of this problem (random variable)?

    What did you do? Did you use the Discrete Binomial Distribution and why do you have 10/32 in the middle?
  14. E

    Undergrad How do we calculate the expected value E(X) for a density function?

    I am requesting an example for a density function and not a mass function.
  15. E

    What's the expected value of this problem (random variable)?

    Didn't see that. I don't even know what that means.