Question

question five
the class levels of 30 students in an elementary statistics course are as follows:
fr so so jr jr jr jr fr so fr so so so fr sr so jr so so jr
sr jr so fr sr sr fr so jr jr
a) construct a frequency distribution
b) add a relative frequency column to the frequency distribution.
c) what percent of the data are sophomores?
d) how many students are juniors?

Explanation:

Step1: Count class - level frequencies

Let's count the number of each class - level:

Class Level	Frequency
So (Sophomore)	12
Jr (Junior)	8
Sr (Senior)	3

Step2: Calculate relative frequencies

The relative frequency of a class is calculated as $\text{Relative Frequency}=\frac{\text{Frequency}}{\text{Total number of data points}}$. The total number of data points is $n = 30$.

Class Level	Frequency	Relative Frequency
So	12	$\frac{12}{30}=0.4$
Jr	8	$\frac{8}{30}\approx0.267$
Sr	3	$\frac{3}{30}=0.1$

Step3: Calculate percentage of sophomores

The percentage of sophomores is the relative frequency of sophomores multiplied by 100. Since the relative frequency of sophomores is $0.4$, the percentage is $0.4\times100 = 40\%$.

Step4: Determine number of juniors

From the frequency - distribution table, the number of juniors is 8.

Answer:

a)

Class Level	Frequency
So	12
Jr	8
Sr	3

b)

Class Level	Frequency	Relative Frequency
So	12	$\frac{12}{30}=0.4$
Jr	8	$\frac{8}{30}\approx0.267$
Sr	3	$\frac{3}{30}=0.1$

c) 40%
d) 8