Section 2.1

9

a)69%

b)55.2million

c)Inferrential statement. Because from this statement we can know a clear result of what 8% of adult Americans believe. It is showing a clear direction.

11

  1. 0.42;0.62

  2. 55+

  3. 18-34

d)With the ages increase, more likely would people buy the American products.

13

datt <- c(0.0262,0.0678,0.1156,0.2632,0.5272)

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    0.0262
## 2       Rarely    0.0678
## 3    Sometimes    0.1156
## 4 Most of time    0.2632
## 5       Always    0.5272
  1. 52.7%

c)9.4%

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"))

g)It is a descriptive statement because it is only showing the data not giving out a conclusion.It is just reporting the information.

15

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

b)23.71%

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"))

f) only by stating the data is not comprehensive. Because this data only represents a small range of people not all of them.

Section 2.2

9

a)8

b)2

c)15

d)4

  1. 15%

f)bell-shaped.

10

a)4

  1. 9

  2. 17.3%

d)Skewed right.Because the whole histogram is leanning to the right and most of the numbers are in the right side.

11

a)200

  1. 10

  2. 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;

  3. 100-109

  4. 150-150

  5. 5.5%

  6. no

12

  1. 200

  2. 52

c)0-199

d)Skewed right.most of the values are in the right side or leanning to the right.

  1. We can’t determine the result just by considering the data that we had. Because there so much more reasons that will affect the situations in Texas and Vermont. So we have to control the variables into specific situations.

13

a)Skewed right. Because most of the household earn $5,000 to 10,000 around. only some of the extreme makes even more. so the higher the incomes, more right to the side.

  1. Bell-shaped. most of the students’ scores will be in the average which is in the middle and only the small amount of students will be lower or higher. Most of the values will be in the middle.

  2. Skewed right. most of the household will have a certain number of people. only a few will have even more numbers of people. so it must be the Skewed right.

d)Skewed left. only older age of people tend to get this illness more likely. with the increase of the age, bigger numbers will be in the right.

14

a)Skewed left. More drinks will be consumed around friday and weekend so it will have bigger numbers in the right.

b)Uniform. Almost all the students get into the public school at the same ages. so it will more likely be the uniform.

  1. Skewed left. Because from our daily life, the older people tend to join the hearing-aid more than the young kids so it will have bigger value on the right side.

d)Bell-shaped. Because most of the full-grown men’s heights are in the almost same number. only a few varies differently. so the most values will be in the middle.

15

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

b)24%

  1. 60%
  1. 0.32;0.22;0.18;0.14;0.04;0.06;0;0.02;0;0.02;

b)14%

c)2%

d)4%