Topic 2: Health value of cereals

You can input the data into RStudio from the following table or download/upload the .csv file provided in the zip folder in the ‘Downloads‘ section in Step 2.13 that lists 20 popular cereals and the amounts of sodium (in milligrams) and sugar (in grams) contained in a single serving. The amounts are rounded to the nearest integer. The variable ‘Type’ classifies the cereal as being popular with adults (A) or children (C). The data is repeated in this table if you would find it easier to input into RStudio compared to the .csv file already given in the earlier hyperlink.

Cereal	Sodium (mg)	Sugar (g)	Type
Frosted Mini Wheats	0	11	A
Raisin Bran	340	18	A
All Bran	70	5	A
Apple Jacks	140	14	C
Cap’n Crunch	200	12	C
Cheerios	180	1	C
Cinnamon Toast Crunch	210	10	C
Crackling Oat Bran	150	16	A
Fiber One	100	0	A
Frosted Flakes	130	12	C
Froot Loops	140	14	C
Honey Bunches of Oats	180	7	A
Honey Nut Cheerios	190	9	C
Life	160	6	C
Rice Krispies	290	3	C
Honey Smacks	50	15	A
Special K	220	4	A
Wheaties	180	4	A
Corn Flakes	200	3	A
Honeycomb	210	11	C

Answer the following questions:

• Obtain the sample means, standard deviations and summary tables for the variables ‘Sodium’ and ‘Sugar’.
• Construct dot plots and box plots for the sodium and sugar values.
• Construct histograms for the sodium and sugar values. If necessary, experiment with different choices of breaks.
• Describe the shape of the distributions of sodium and sugar. Is a normal approximation appropriate? Is there anything unusual in the distribution of sugar? What could be an explanation? (Referring to ‘Type’ may be useful.)