# I need the problems on the attached worksheet solved

Statistics 20 Midterm Fall 2018 – Instructor: Hank Ibser1. You don’t need to simplify answers for this problem, they can be left as unreduced fractions
with multiple terms. Two boxes have colored balls in them. Box A has 3 blue and 7 red balls
in it, box B has 2 blue and 1 red.
(a) Three balls are selected without replacement from box A and one ball is selected from
box B. What is the chance that at least one of these balls is blue?
(b) A random box is selected, and then 10 balls are selected with replacement all from that
random box. Find the chance that there are exactly 4 blue balls in the 10 draws.
2. In an exercise class, participants are timed running a mile. The times (in minutes) are
summarized in the table below, but some values are missing.
(a) Fill in the table and draw the corresponding histogram. If you can’t figure out the table,
just put in anything and draw a histogram. More than one answer may be possible.
Time Percent Height of bar
5-6
10
6-7
20
7-8
25
8-10
15
10-15
(b) Assuming that the percent in each bar is spread evenly for every interval, find the 45th
percentile as accurately as possible.
(c) Do you think the percent of people who took an above average amount of time is less
than 50%, about 50%, or more than 50%? Explain briefly (one line is OK).
3. Suppose that the data from the previous problem is in a data frame called data which has two
columns: miletime with the data used for the table on the previous page, and a logical vector
called smoker that is TRUE for everyone who is a current smoker and FALSE for everyone
else.
(a) Write code to find the mean time to run a mile for both smokers and non-smokers.
(b) Using the same data frame as in a), write code using ggplot() to make a histogram for
the mile times for just the smokers, with the same class intervals as on the previous page
(you can assume there aren’t any values at the endpoints of those intervals if that makes
(c) In making the histogram in part b) did you ever use an argument called y? Whether you
used it or not, what does that argument mean in this context?
4. I have a box with 40 tickets: 37 marked 1 , 1 marked 2 , 1 marked 3 , and 1 marked 38 .
For each part of this question, use normal approximation if you think it is appropriate (look
up area on table or use calculator). If you don’t think it’s appropriate say why not and if
possible find the chance in some other way.
(a) In 30 draws, find the chance that the sum of draws is 30 or less.
(b) In 40 draws, find the chance that the sum of the odd numbers is 43 or more.
(c) Write a line of code in R that will answer the following question as accurately as possible.
In 50 draws, find the chance that the number of times I draw a 1 is 43 or more.

Don't use plagiarized sources. Get Your Custom Essay on
I need the problems on the attached worksheet solved
Just from \$13/Page
Pages (550 words)
Approximate price: -

Why Work with Us

Top Quality and Well-Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Free Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.

Prompt Delivery and 100% Money-Back-Guarantee

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

## Calculate the price of your order

Total price:
\$0.00

How it works?

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.

## Essay Writing Service

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.