Basic R

Question 1

Get subset of data

Answer 1

subset(mdata = cdc, gender == “m” & age > 40)

Question 2

Compute the relative frequency distribution for gender in dataset

Answer 2

table(cdc$gender) / 20000(totalnumberofdata) = males 52,1%

Question 3

compute interquartile range

Answer 3

Subtract Q1 from Q3 to find the interquartile range.

Question 4

help.search()

Answer 4

Help search

Question 5

get a summary and use descriptive stastistics in dataset

Answer 5

summary(dataset)

Question 6

main =

Answer 6

edit the header text of graph

Question 7

col =

Answer 7

color your graph

Question 8

all_equal()

Answer 8

all_equal() allows you to compare data frames, optionally ignoring row and column names.

Question 9

Prop =

Answer 9

Compute proportions, percents, or counts for a single level

Question 10

Ctable ()

Answer 10

Cross-tabulation for a pair of categorical variables (or factors) with either row, column, or total proportions, as well as marginal sums

Question 11

range()

Answer 11

R has a function range which applied to a vector v returns a two-component vector comprising the minimal and maximal component of v.

Question 12

var

Answer 12

Variance is the spread a variable around the means.

R has a function var for computing the variance.

Question 13

pnorm()

Answer 13

Calculating percentiles - using computation
> pnorm(1800, mean = 1500, sd = 300)
[1] 0.8413447

Question 14

Define a function

Answer 14

Create a function to print squares of numbers in sequence.

new.function

Question 15

Simulations in R

Answer 15

Use the sample() function to determine the probability of rolling a 7 using three fair six-sided dies.

trials