Enable contrast version

Tutor profile: Ngan H.

Ngan H.
Tutor and instructor for 5 years

Questions

Subject: Basic Math

TutorMe
Question:

Solve this system of equations: $$ \left\{ \begin{array}{ccc} \displaystyle 3(e+f) & = & 5e + f + 2\\\\ \displaystyle 4(f-e) & = & e + 2f - 4 \end{array} \right. $$

Ngan H.
Answer:

Solving the first equation for $f$ gives \begin{align*} 3(e+f) & = 5e + f + 2\\ \Longrightarrow ~ 3e + 3f & = 5e + f + 2\\ \Longrightarrow ~~ 3f - f & = 5e - 3e + 2\\ \Longrightarrow \quad\quad\quad f & = e+1 \end{align*} Substituting for $f$ in the second equation gives \begin{align*} 4(f-e) & = e + 2f - 4\\ \Longrightarrow ~ 4((e+1) - e) & = e + 2(e+1) - 4\\ \Longrightarrow ~~\quad\quad\quad\quad\quad 4 & = e + 2e + 2 - 4\\ \Longrightarrow ~~\quad\quad\quad\quad\quad e & = 2 \end{align*} This means, $f = e + 1 = 2 + 1 = 3$.\\\\ Thus, $e = 2$ and $f = 3$.

Subject: Statistics

TutorMe
Question:

In a poll conducted by the General Social Security, 81\% of respondent said that their jobs were sometimes or always stressful. Ten workers are chosen at random. \begin{enumerate}[(a)] \item Let $X$ be the number of respondents who find their job stressful among ten selected workers. Does $X$ follow a Bernouli or binomial distribution?\\ \item What is the probability that \underline{exactly} 7 of them find their jobs stressful?\\ \item What is the probability that \underline{no more than} 7 of them find their jobs stressful?\\ \item What is the probability that \underline{more than} 7 find their jobs stressful?\\ \item What is the mean number who find their jobs stressful in this study?\\ \item What is the standard deviation of the number who find their jobs stressful in this study?\\ \end{enumerate}

Ngan H.
Answer:

In a poll conducted by the General Social Security, 81\% of respondent said that their jobs were sometimes or always stressful. Ten workers are chosen at random. \begin{enumerate}[(a)] \item Let $X$ be the number of respondents who find their job stressful among ten selected workers. Does $X$ follow a Bernouli or binomial distribution?\\ {\color{red} $X$ follows a binomial distribution. } \item What is the probability that \underline{exactly} 7 of them find their jobs stressful?\\ {\color{red} $P(X=7) = $ binompdf$(10,\ 0.81,\ 7)=0.1883$ } \item What is the probability that \underline{no more than} 7 of them find their jobs stressful?\\ {\color{red} $P(X \leq 7) = $ binomcdf$(10,\ 0.81,\ 7)=0.2922$ } \item What is the probability that \underline{more than} 7 find their jobs stressful?\\ {\color{red} $P(X > 7) = 1 - P(X \leq 7) = 1-0.2922 = 0.7078$ } \item What is the mean number who find their jobs stressful in this study?\\ {\color{red} $\mu = np = 10 \times (0.81) = 8.1$ } \item What is the standard deviation of the number who find their jobs stressful in this study?\\ {\color{red} $\sigma^2 = np(1-p)=10\times(0.81)\times(1-0.81)=1.539 \quad\Longleftrightarrow \sigma = \sqrt{\sigma^2} = \sqrt{1.539}=1.2406 $ } \end{enumerate}

Subject: Algebra

TutorMe
Question:

Given a quadratic function $\displaystyle p(x) = 2.019 x^2 - 20.19 x + 2019$. Evaluate $p(3-4a)$ and \underline{simplify} as much as it can be \textit{(you have to show your work)}.

Ngan H.
Answer:

\begin{align*} \displaystyle p(3-4a) &=2.019(3-4a)^2-20.19(3-4a) + 2019\\ &=2.019(3-4a)(3-4a)-20.19(3-4a) + 2019\\ &=2.019(9 - 24a + 16a^2) - (60.57 - 80.76a) + 2019\\ &=18.171 - 48.456a + 32.304a^2 - 60.57 + 80.76a + 2019\\ &=32.304a^2+32.304a+1976.601 \end{align*}

FAQs

What is a lesson?
A lesson is virtual lesson space on our platform where you and a tutor can communicate. You'll have the option to communicate using video/audio as well as text chat. You can also upload documents, edit papers in real time and use our cutting-edge virtual whiteboard.
How do I begin a lesson?
If the tutor is currently online, you can click the "Start Lesson" button above. If they are offline, you can always send them a message to schedule a lesson.
Who are TutorMe tutors?
Many of our tutors are current college students or recent graduates of top-tier universities like MIT, Harvard and USC. TutorMe has thousands of top-quality tutors available to work with you.
BEST IN CLASS SINCE 2015
TutorMe homepage
Made in California by GoGuardian
Copyright © 2022. Zorro Holdco, LLC doing business as TutorMe.
All Rights Reserved.
High Contrast Mode
On
Off