UCLA Statistics Worksheet
UnauthorizedHomework 3: Descriptive Statistics, Normal Distribution, and
Recoding
write your name here
Part 1. From the week 3 lecture
Are the following statements True or False?
Please add a brief explanation to support your choice.
QUESTION 1
• Statement: Both central tendency and variability are useful to describe the shape of a distribution.
• True or False:
• Description:
QUESTION 2
• Statement: Standard deviation score of 1 means that 84.1% people fall at or below the score.
• True or False:
• Description:
Part 2. From the week 3 discussion
Before you get started, please import grit_score.csv (the new file you wrote at the end of Module 3) with
a new code chunk. It will make you able to work on questions. Preferred object name is grit, but you can
take another object name for the data.
QUESTION 1
There is a variable that corresponds to whether the respondent has voted in a national election in the past
year. Recode those values according to the codebook. Then create a frequency table based on those recoded
values.
QUESTION 2
For now, we can treat the interval responses to the item “I have overcome setbacks to conquer an important
challenge” as continuous. Create a five-number summary of the responses to that item and describe what
each number means.
1
QUESTION 3
Using the rnorm() function, draw 2000 samples from the normal distribution with mean 2 and variance 4.
Store those samples in a variable of your choice.
QUESTION 4
Selects columns that correspond to grit scale items 2, 3, 5, 7, 8, and 11.
2
