# MATH 2565 Study Guide - Midterm Guide: Roadside Attraction, Jungle Island, Impulse PurchaseExam

by OC1317869

School

York UniversityDepartment

Mathematics and StatisticsCourse Code

MATH 2565Professor

Cindy Fu YuejiaoStudy Guide

MidtermThis

**preview**shows pages 1-2. to view the full**6 pages of the document.**York University

MATH 2565 (Winter 2016): Introduction to Applied Statistics

Midterm II Examination โ Thursday March 17, 2016, 10 am - 11:10 am

Last Name: Given Names:

Student Number:

Signature :

DO NOT WRITE IN THIS AREA

Read the following instructions carefully

1. Students are allowed to bring: a. One one-sided

8.5โx11โ formula sheet b. Calculator(s) (cannot use

laptop, cell phone or ipad as calculator)

2. All work must be done in the free space provided be-

low for each problem or on the back of the preceding

page.

3. No other sheets of paper will be accepted or marked.

4. This exam consists of 9 pages in total. Last 3 pages

contain three tables.

Question Max Score Your Score

1 10

2 10

3 10

4 10

5 10

TOTAL 50

1

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

Question 1 (10 marks) Research concerning purchasing habits at the grocery store suggests

that impulse buys make up 60% of all purchases. Suppose 100 customers are selected at

random.

(a) Let Xbe the number of customers who make an impulse purchase out of the 100

randomly selected customers. Find the mean and variance of X.

Solution ยต=np = 100(.6) = 60, ฯ2=np(1 โp) = 100(.4)(.6) = 24

(b) Find the variance of the sample proportion หp=X

n.

Solution varหp=p(1โp)

n=.6(.4)

100 =.0024

(c) ๏ฌnd the probability that at most one customer makes an impulse purchase.

Solution๎100

0๎(.4)100 + +๎100

1๎(.6)(.4)99 โผ0

2

###### You're Reading a Preview

Unlock to view full version