1. Sometimes it is difficult to understand data if you do not know what the numbers represent. Provide short definitions of two words: sepal, and petal. A sepal is a noun that describes the outer most aspect of a flower that protects the developing flower, usually appearing as “white or green in color” (Cambridge English Dictionary, n.d.).
A petal is a noun that describes the most common part of the flower that varies in colors and surrounds the reproductive parts of the flower (The Free Dictionary, n.d.).2. There is a cumulative relative frequency table printed above for petal lengths (using rounded values for petal length). Below the number 3 in that table is the number .
35. What does .35 represent?The value of .
35 represents “d. Of all the flowers measure in this sample 35% had a petal length of 3 or less (after rounding the petal lengths)”. The table is a “cumulative frequency table” meaning that this table accumulates the current relative frequency to the previous relative frequency for each value in the table (Yakir, 2011).3. Using only the cumulative relative frequency table printed above combined with some simple paper-and-pencil calculations, which petal length occurs most frequently?To find the answer, see the graph and rationale below.Value: 1 2 3 4 5 6 7CumulativeRelative Frequency (CRF): 0.
16 0.33 0.35 0.58 0.81 0.97 1.
00How arrived at RF 0.16 0.33-0.
16= 0.35-0.33= 0.58-0.35= 0.
81-0.58= 0.97-0.81= 1.00-0.97=Relative Frequency (RF): 0.
16 0.17 0.02 0.23 0.23 0.
16 0.03As you can see, there are two (2) petal lengths that occur most frequently which is value 4 and 5.4. Describe how you determined your answer to the previous question (describe the calculations that you used). I started at the 7 value with the Cumulative Relative Frequency (CRF) of 1.00 and deducted the CRF for the 6 value (i.
e., 1.00-0.97=0.03) meaning that the Relative Frequency for the 7 value is 0.
03 or (0.03 x 100 = 30) 3% of the total observations of that variable (Yakir, 2011).5. Assuming that you read the flowers.csv file into an R object called flower.data, run the following R code (do not paste the “>” character into R) and paste both the command and the output into you answer:>names(flower.
data)>names(flower.data)1 “Sepal.Length” “Sepal.Width” “Petal.Length” “Petal.
Width” “Species”6. The number of observations in the “flower.data” data frame is 150 observations.7.
List the variables in the data frame (you can do this by entering the name of the R object that holds that data that you read using the read.csv command—you should have called it flower.data).
For each variable identify the type of the variable (factor or numeric). Name of Variable Type of Variable (factor or numeric)1st variable Sepal.Length Numeric2nd variable Sepal.Width Numeric3rd variable Petal.Length Numeric4th variable Petal.Width Numeric5th variable Species Factor8.
Round the data for the variable Sepal.Length so that it contains integers, then find the frequency of the value 7 (not the relative frequency): This answer took me a while and I utilized the help menu in R to figure it out but I found the answer by the following process:>datsepal=round(dat$Sepal.Length,0)>table(sepal)Sepal4 5 6 7 85 47 68 24 6Resulting in the answer “find the frequency of the value 7 which is 24.9. What is the sum of the first three frequencies in the frequency table for septal width? The sum is found by adding 1 + 3 + 4 = 8. 8 is the sum of the first three frequencies in the table.
10. What does your answer to the previous question represent (in terms of sepal width and frequency and the percentage of all sepal measurements)? It reflects the number of observations of the frequency of the variable (sepal width) within the sample of the population.11. What is the sum of the last three frequencies in the frequency table for sepal width?The sum is found by adding 1 + 1 + 1 = 3. 3 is the sum of the last three frequencies in the table.
12. How many flowers in the sample had sepal widths less than 4? This is found by summing all the first 19 relative frequencies since they reflect all of the numeric observations for sepal widths less than 4. (i.e. 1+3+4+3+8+5+9+14+10+26+11+13+6+12+6+12+6+4+3+6+2=146). 146 flowers had sepal widths less than 4.
13. What does the tallest bar in the plot represent? (Multiple choice)b. mode – the relative frequency that occurs the most (Khan Academy, n.d.
)14. Create a frequency table that shows the frequencies for each species of flower in the sample. Paste your R command and output into your answer.>table(flower.
data$Species)setosa versicolor virginica50 50 5015. Explain two things about the table that you created for the previous task:Why did the frequency table for flower species contain words in the first row as opposed to numbers? The reason that words are contained in the first row is because this variable was a factor or qualitative data which described that factor or data regarding the observations made of the sample within the population.What is the meaning of the numbers in the second row of the table? The second row containing numeric data shows how many of the observations made of the sample within the population represented that particular species. Interestingly enough, each species represented 1/3 of the total population (i.e.
50 + 50 + 50 = 150). 150 was the total number of observations made.ReferencesKhan Academy (n.
d.). Mean, median, and mode review. Retrieved November 27, 2018, from https://www.khanacademy.
org/math/statistics-probability/summarizing-quantitative-data/mean-median-basics/a/mean-median-and-mode-reviewpetal. (n.d.) American Heritage® Dictionary of the English Language, Fifth Edition. (2011).
Retrieved November 27 2018 from https://www.thefreedictionary.com/petalsepal. (n.
d.) Cambridge English Dictionary. (n.d.
). Retrieved November 27, 2018, from https://dictionary.cambridge.org/dictionary/english/sepalYakir, B. (2011).
Introduction to statistical thinking (with R, without calculus). Retrieved November 26, 2018.