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1 answer:
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Answer:
Q1
slope=0.16
intercept=30.2
Q2
78.2
Q3
36%
Step-by-step explanation:
Question 1
We are given that
xbar=280
sx=30
ybar=75
sy=8
r=0.6
The regression line can be written as
y=a+bx
a=intercept
b=slope
where
and
b=0.6*(8/30)
b=0.16
a=75-0.16*280
a=30.2
Thus,
slope=0.16
intercept=30.2
Question 2
The regression line in the given scenario
y=30.2+0.16x
Julie pre exam total before the exam was 300.
y=30.2+0.16*300
y=30.2+48=78.2
So, the predicted final exam score of Julie is 78.2.
Question 3
R² denotes the variation in dependent variable y explained by the linear relationship of x and y.
R²=0.6²=0.36
Thus, the proportion of the variation in final exam scores that is explained by the linear relationship between pre-exam scores and final exam scores is 36%.
Answer:
0.5234 = 52.34% probability that at least three of these students are in favor of the proposal to change the dress code.
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they are in favor, or they are not. Students are independent. This means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
18% of the students are in favor of changing the dress code.
This means that
You randomly select 15 students
This means that
What is the probability that at least three of these students are in favor of the proposal to change the dress code?
This is
In which
In which
0.5234 = 52.34% probability that at least three of these students are in favor of the proposal to change the dress code.