Section 2.1

9

  1. Approximately 70%

  2. 55.2 million adults in America believe divorce is morally wrong.

  3. This statement is descriptive because it uses numerical data to characterize the population.

11

  1. 45% of 18-34 year old respondents are more likely to buy when made in America. 61% of 35-44 year old respondents are more likely to buy when made in America.

  2. 55 year old respondents have the greatest proportion who are more likely to buy when made in America.

  3. The 18-34 age group has a majority of respondents who are less likely to buy when made in America.

  4. The older the demographic, the more likely they are to buy when made in America.

13

  1. Never= 0.26; Rarely= 0.68; Sometimes= 0.12; Most of the times= 0.26; Always= 0.53
datt <- c(125, 324, 552, 1257, 2518)

rel.freqq <- datt/sum(datt)

categoriess <- c("Never", "Rarely", "Sometimes", "Most of time", "Always")


answerr <- data.frame(categoriess,rel.freqq)

answerr
##    categoriess  rel.freqq
## 1        Never 0.02617253
## 2       Rarely 0.06783920
## 3    Sometimes 0.11557789
## 4 Most of time 0.26319095
## 5       Always 0.52721943

  1. Approximately 52% of respondents answered “always”

  2. Approximately 2.6% of respondents answered “never” and 6.7% of respondents answered “rarely”.

barplot(datt,main="Seat Belt Usage",names=categoriess, col =c("red","blue","green","yellow","orange"))

barplot(rel.freqq,main="Seat Belt Usage",names=categoriess, col =c("red","blue","green","yellow","orange"))

pie(datt,main="Seat Belt Usage",labels=categoriess, col =c("red","blue","green","yellow","orange"))

  1. The statement is inferential because they are making an estimation without using every single college student in the study. Therefore, without conclusive data, it is inferential.

15

  1. More than 1 hour = 0.37 Up to 1 hour a day = 0.19 A few times a week = 0.13 A few times a month or less = 0.08 Never = 0.24
dat <- c(377,192,132,81,243)

rel.freq <- dat/sum(dat)

categories <- c("More 1", "Up to 1", "Few a week", "Few a month", "Never")


answer <- data.frame(categories,rel.freq)

answer
##    categories   rel.freq
## 1      More 1 0.36780488
## 2     Up to 1 0.18731707
## 3  Few a week 0.12878049
## 4 Few a month 0.07902439
## 5       Never 0.23707317

  1. Approximately 23%.

barplot(dat,main="Internet Usage",names=categories, col =c("red","blue","green","yellow","orange"))

barplot(rel.freq,main="Internet Usage(Relative Freq)",names=categories, col =c("red","blue","green","yellow","orange"))

pie(dat,main="Internet Usage",labels=categories, col =c("red","blue","green","yellow","orange"))

Section 2.2

9

  1. The most frequent outcome of the experiment was 8.

  2. The least frequent outcome of the experiment was 2.

  3. We observed a 7 rolled 15 times.

  4. 5s were observed 4 more times than 4 (11 vs. 7)

  5. A 7 was observed 15% of time.

  6. The distribution is skewed left because the left tail is longer than the right tail.

10

  1. The most frequent number of cars sold in week is 4.

  2. 2 cars were sold in 9 weeks.

  3. 9/52= 0.173. 2 cars were sold 17.3% of time.

  4. Since the tail is longer on the right, the shape of the distribution is skewed right.

11

  1. 200 students were sampled.

  2. (160-60)/10= 10.

  3. 60-69= 2; 70-79= 3; 80-89= 13; 90-99= 42; 100-109= 58; 110-119= 40; 120-129= 31; 130-139= 8; 140-149= 2; 150-159= 1.

  4. 100-109.

  5. 150-159.

  6. 5.5%

  7. No.

12

  2. 0-199; 200-399; 400-599; 600-799; 800-999; 1000-1199; 1200-1399.

  3. 0-199.

  4. Skewed right.

  5. This statement is wrong because it implies that the roads are what cause alcohol-related deaths without even taking into account consumption of alcohol or any other variable.

13

  1. Skewed right because the frequency would be greater on the left with middle and lower class versus upper class.

  2. Bell shaped because the most scores are average, with the exception of those who do really well and those who do poorly..

  3. Skewed right because most households consist of 1-4 members .

  4. Skewed left because Alzheimer’s disease is typically diagnosed in the elderly.

14

  1. Skewed left because people usually drink more on the weekend.

  2. Uniform because each grade usually has around the same amount of students.

  3. Skewed left because most patients with hearing aid are older.

  4. Bell shaped because full grown men tend to be taller in their mid life.

15

  1. 0: 0.32; 1: 0.36; 2:0.24; 3:0.06; 4:0.02
dattt <- c(16, 18, 12, 3, 1)

rel.freqqq <- dattt/sum(dattt)

categoriesss <- c("Zero", "One", "Two", "Three", "Four")

answerrr <- data.frame(categoriesss,rel.freqqq)

answerrr
##   categoriesss rel.freqqq
## 1         Zero       0.32
## 2          One       0.36
## 3          Two       0.24
## 4        Three       0.06
## 5         Four       0.02

  1. 24%.

  2. 60%.