MGSC 291 Homework Questions
length(price) - ANS-how do you find length of the "price" column?
length(price[!is.na(price)]) - ANS-how do you find how many observations have a price?
mean(points) - ANS-how do you find the average points?
mean(price,na.rm=TRUE) - ANS-how do you find average price?
mean(points[region_2=="Sonoma"]) - ANS-how do you find average points for Sonoma
considering region_2?
mean(price[region_2=="Sonoma"],na.rm=TRUE) - ANS-how do you find the average price for
Sonoma considering region_2?
time series - ANS-A marketing company requested the daily sales for each day in the past year
for all locations of Zales - cross-sectional or time series?
cross sectional - ANS-a real estate agent pulls the sales records for all similar homes sold in the
area in the past month - cross-sectional or time series?
time series - ANS-in preparation for a shareholder meeting, records were pulled for quarterly
sales over the past 5 years - cross sectional or time series?
line graph - ANS-what graph works best for - quarterly sales for Starbuck's coffee
bar graph - ANS-what graph works best for - annual sales for top 10 corporate stores
histogram - ANS-what graph works best for - annual sales for all of the 27,339 stores. you want
to show there are two modes
side by side boxplots - ANS-what graph works best for - show annual sales for the 27,339
stores broken down by corporate vs. non-corporate
scatterplot - ANS-what graph works best for - data displaying the relationship btw advertising
and dollars for all 27,339 stores
chevychev's - ANS-the histogram is skewed right. what do you use to estimate the percent of
observations within 2 standard deviations of the mean?
length(price) - ANS-how do you find length of the "price" column?
length(price[!is.na(price)]) - ANS-how do you find how many observations have a price?
mean(points) - ANS-how do you find the average points?
mean(price,na.rm=TRUE) - ANS-how do you find average price?
mean(points[region_2=="Sonoma"]) - ANS-how do you find average points for Sonoma
considering region_2?
mean(price[region_2=="Sonoma"],na.rm=TRUE) - ANS-how do you find the average price for
Sonoma considering region_2?
time series - ANS-A marketing company requested the daily sales for each day in the past year
for all locations of Zales - cross-sectional or time series?
cross sectional - ANS-a real estate agent pulls the sales records for all similar homes sold in the
area in the past month - cross-sectional or time series?
time series - ANS-in preparation for a shareholder meeting, records were pulled for quarterly
sales over the past 5 years - cross sectional or time series?
line graph - ANS-what graph works best for - quarterly sales for Starbuck's coffee
bar graph - ANS-what graph works best for - annual sales for top 10 corporate stores
histogram - ANS-what graph works best for - annual sales for all of the 27,339 stores. you want
to show there are two modes
side by side boxplots - ANS-what graph works best for - show annual sales for the 27,339
stores broken down by corporate vs. non-corporate
scatterplot - ANS-what graph works best for - data displaying the relationship btw advertising
and dollars for all 27,339 stores
chevychev's - ANS-the histogram is skewed right. what do you use to estimate the percent of
observations within 2 standard deviations of the mean?
