1. P

    Confidence Intervals Question Checking work

    Hello! I'm looking for any kind of advice to start this problem. Please don't just give me the answer. Explain how to do the problem! Thanks! Suppose we are interested in modeling the distribution of tread life for a premium brandof radial tire. Assuming that the life of the tires are normaly...
  2. T

    Checking if a point is on a plane

    So Im given 3 points that define a plane: A=(2, 1,3) B=(-1,4,1) O=(0,0,0) And am asked if the point p=(1, - 1,2) is on the same plane. I reached the conclusion it isn't. I wonder if you can understand anything from that pic... I intended to edit it but tapatalk doesn't let me before/after...
  3. M

    Right Triangle Problem (Answer Checking)

    A building contractor wants to put a fence around the perimeter of a flat lot that has the shape of a right triangle. one angle of the triangle is 41.4 degrees, and the length of hypotenuse is 58.5m. Find the length of the fencing required. Round the answer to one decimal place. I got h =58.5...
  4. A

    Checking the endpoints of the interval of convergence

    These problems are fairly easy, but it's the arithmetic with the terms that gets me. I don't know if I simplified the terms highlighted in yellow.
  5. A

    Checking the endpoints of the interval of convergence

    I just wanted to check if my conclusion about the interval of convergence is correct.
  6. A

    Checking answer for improper integral

    I evaluated the improper integral and got 1/2. I checked wolfram and typed in two versions of the problem and got 2 different answers. Which version is correct?
  7. R

    parabola and x-intercept, checking the work.

    Hey there, finding the x intercepts of this parabola vertex is (1,-13) and y intercept is (0, -11) answer in (x1, y1), (x2, y2) So i used y = a(x-h)^2 + k (h, k) = (1, -13) y = a(x-1)^2 + -13 solved: -11 = a(0-1)^2 + -13 ....+2 = a(1) a = 2 So now, y =...
  8. Z

    Ratio Checking Problem

    hello all.. i have problem : if a:b = 5:4, b:c = 3:5, if c-a = 75000, find a+b+c = ...? a) 555000 b) 705000 c) 715000 d) 755000 i have tried : {(5*3)+(4*3)+(4*5)}/(20-15)*75000 : {47/5}*75000 = 705000 (answer b) it's true my answer?
  9. C

    Checking if answer is correct. Ellipse

    Hey Guys, I am just wondering if my steps and answers look correct. I would love the feed back. Thanks
  10. B


    Region yes no ttl 1 250 100 350 2 320 110 430 3 560 150 710 4 440 70 510 TOTAL 1570 430 2000 HELLO - I am doing this assignment and no answers in my book. Wondering if I got the answers correct? I hate probability just so you know. haha but it's fun. The...
  11. D

    f(x+h) function equation: help checking work (long)

    I am brand new to pre-calculus, and have little experience with functions. Please check my work, and comment on any errors in my process. I appreciate the help. Here is the question: Given f(x) = -7x^3 -3x^2 + 5x -4 , find and simplify the following as much as possible: f(x+h) - f(x) / h...
  12. T

    need help checking my answers please.

    Can someone please check my answers: I got: sin 12/13 cos -5/13 tan -12/5 and obvious reciprocals. I got it wrong! :( where did I go wrong?
  13. K

    Checking HW

    A research report says that t (142) = 2.56; p = .06. From that information, can you reject the null hypothesis with 95% confidence? wo children draw straws for chores on a weekly basis. The two chores up for grabs are cleaning the bathroom or vacuuming the rugs. After 10 weeks, one child...
  14. BERMES39

    Checking the divergence theorem on a sphere

    I have not been able to solve this problem. Can someone please help me find the error?
  15. C

    Checking relations for reflexivity, transitivity, symmetry and anti symmetry.

    The first part of my assignment was creating 9 relations based on the set M := {A,B,C} itself with ascending cardinality I ended up having this, I was assured that this is correct: R1= {(A,A)} R2= {(A,A),(A,B)} R3= {(A,A),(A,B),(A,C)} R4= {(A,A),(A,B),(A,C),(B,A)} R5=...
  16. A

    Checking validity of proof

    I would like to check if my proof of this proposition has been correctly done. I would also like help on proving part (c). Thanks in advance. **Proposition:** Let $H$ be a subgroup of a group $G$, and let $N$ be the normalizer of $H$. Prove that: (a) $H$ is a normal subgroup of $N$ (b)...
  17. F

    Easy Differentiation -- Double Checking

    Find the co-ordinates of the points on the curves given by the following equation at which the gradient has the given value: y = x2 - 3x + 1, gradient = 1. To solve this, I found the derivate of the function: dy/dx = 2x - 3 and equated it to 1 and solved for x, giving me x = 2. Is this correct...
  18. M

    Need help checking a double integration problem

    double integral of( (1+x^2)/(1+y^2) ) dA , R= [0,1] x [0,1] the R is under the double integral I chose to integrate x first and I got Pi/3, if the answer is incorrect I'll post my work but I just want to make sure I have the right answer for this problem.
  19. E

    OLS: checking the whether the difference between two variables is significant

    Hi everybody! I have a question about hypothesis testing in ordinary least squares regressions. I have 4 OLS regression coefficients and I know each of their standard errors. They are b1, b2, b3, and b4. What I am trying to figure out is if (b1-b2) - (b3-b4) is statistically significant from...
  20. I

    checking proof that no natural number can be both even and odd

    Hi I am here after a long time. I want to prove that no natural number can be both even and odd. This is from basic analysis book. So I start by saying that let S be the set of natural numbers such that they are both even and odd. S=\{ n\in \mathbb{N}| \mbox{ n is even and n is odd} \} I...