interval

  1. S

    Smallest interval for existence of unique solution of differential equation

    The smallest interval on which a unique solution exist for the IVP y′=e^(2y), y(0)=0, is what? A)|x|<=1/2e B)|x|<=2e C)|x|<=2/e D)|x|<=1/e I am confused which one is correct. Please help.:confused:
  2. L

    Confidence interval, parametric statistics

    I have no clue how to solve it. I can see that it must be rather simple, but I'm so new to stat that I don’t know where to start. If I understand correctly, I have to calculate the P(theta-1/2<theta<theta+1/2) and that should be 0.5, but if theta is on the real number line that probability is...
  3. H

    Confidence interval for the population standard deviation?

    Use the given degree of confidence and sample data to find a confidence interval for the population standard deviation. Assume that the population has a normal distribution. The hockey coach selected eight players at random and timed how long each player took to finish their exercises. The...
  4. D

    Calculate probability of interval with a random variable?

    Hi! I have studied algebra and calculus mostly (Calculus 1), not so much probability. So my problem is that I have a random variable called r that can generate any number from 1 to 100 (1 and 100 are included, interval [1, 100]). I set up a condition that if r >= 1 and r <= 75 then generate a...
  5. N

    interval / radius of convergence

    Any guidance will be appreciated : find the interval of convergence u_n=((2^n (n+2))/n^2 )((2x-1)^n)
  6. R

    Determine the interval of x

    Hello, I have a question here that I have no previous knowledge of, I turn to the internet for help because I am currently studying on my own for a test. I have a question here that to be honest I have no idea about. It states: Determine the interval of x for which (i) x(x+2)> 0 (ii)...
  7. G

    state the domain of the following use set notation and interval notation

    state the domain of the following...thanks I am so clueless f(x)=x
  8. L

    Confidence interval with Bernoulli distribution

    Hello, With have interval (0.45,0.55) and alpha = 0.88 How can calculate 'n' through Bernoulli distribution ? Thanks
  9. Y

    Chebychev, where mean is not in the middle of the estimated interval

    One more question, can you maybe help me again? Fifty-five percent of all students on a campus are in Humanities. If 150 students are selected at random, what is the probability that the proportion of Humanities students in this particular sample will be between 45% and 55%. I did the...
  10. F

    Interval of Convergence

    Im trying to find the interval of convergence of a series. I used the Ratio test for absolute convergence, but that limit ended up being zero. For the other problems i've done, it usually comes out to 1 and then i multiply that by |X| and find the I.O.C. Im not sure what that means when the...
  11. M

    Fourier series expansion without shifting to the given interval

    Given the function $f(x)=f(x+9)$ with $f(x)=x^2-11x+10$ The Fourier series expansion without shifting $f(x)$ on the working interval I will solve the Fourier series on the interval [1,10] thus the Period, P=9 and initial value, c=1 Calculating $a_0$ using the equation, $a_0= \frac{2}{P}...
  12. G

    Quick question on limit of interval

    Hi, is limit of the interval (0, 1/n] as n tends to infinity the point 0, i.e. {0} or totally nothing? I personally think it is 0 but 1/n gets closer and closer to 0 but does not actually touch 0 so I am afraid that I am wrong. I want to make sure. Thanks.
  13. E

    Would People Know If Results Are Within A 95% Confidence Interval 95% Of The Time?

    I was reading about political polling and margin of error. I'm not saying statisticians are wrong about margin of error, but what if hypothetically polls in general are within the 95% confidence interval only 75% of the time? Without asking the entire population, how would people know if the...
  14. Z

    Continuous function on closed interval is bounded.

    Continuous function on closed interval is bounded. Assume f(a) is infinite for some a. Lim f(x) = f(a) finite because f(x) continuous at x=a. Contradiction. f(x) is bounded.
  15. D

    Confidence interval word problem help

    Confidece interval question I have 2 statistics questions that I do not understand fully, can anyone solve these and explain the process for retrieving the answer? Thanks!! A Survey Of 47 mernbers Of a health club reported that prefer walking Or running On a treadmill to any other type of...
  16. P

    how to find global maximum on open interval

    hello, guys, I have a real problem to understand how to find the global maximum of this function (n+5)/radical (n^2+n) on an open interval I studied a lot about it but I could not find something useful about it. I know I should use limit as x approaches to +or- infinity but I confused it...
  17. B

    how to get a symmetric interval from an asymmetric one

    Suppose I have an interval [a,b] that is asymmetric to a given number "c". How to proceed to create a interval that is symmetric and is inside the [a,b] interval?
  18. R

    modal interval and mean?

    help, i need to find this.. this is the table and the questions are 1. write down the modal interval 2. calculate the estimate for the mean.
  19. J

    Find the radius of convergence, and the interval of convergence, of the series.

    Power Series: Find the radius of convergence, and the interval of convergence of the series: \sum_{n=1}^{\infty }\frac{\sqrt{n}(2x+3)^{n}}{n^{2}+1} I have tried to solve this problem as following: \lim_{n\rightarrow \infty }\left | \frac{a_{n+1}}{a_{n}} \right |=\lim_{n\rightarrow...
  20. J

    Confidence Interval

    It is reported that 30% of cars failed the national car test (NCT) at a particular centre in 2014. A random sample of 250 cars was selected from this centre in 2015. From those selected cars, 92 failed the test. a) Calculate the 90% confidence interval for the proportion of cars failing...