Answer:
a. 2:3, b. 25 students, c. 3:2
Step-by-step explanation:
a. 5 (total) - 2 (with glasses) = 3 (without glasses), making the ratio 2:3.
b. We can assign the total students with the variable x. 3:5=15:x, 75=3x, x=25. 25 total students.
c. 25 (total students) - 15 (without glasses) = 10 (with glasses). (10+5):(15-5) is 15:10, which, when simplified, equals to 3:2.
A) If you only sample people in a sports supply store, your sample will be biased. People in a sports supply store are more likely to be people that belong to a gym.
B) While it does not have necessarily the same amount of bias as sampling people in the sports supply store, people that go to a park are generally more likely to be people that exercise or have a gym membership.
C) Taking a random sample of people in town is a good way to get a non-biased sample. They are not necessarily predisposed to answer your question one way or another.
D) For the same reason as choice A, this is a biased sample.
C is the best choice.
Answer:
Option D. 5x + 12y + 4z is the corrct one.
First, find the gradient/slope:
Use slope formula:
m=(y2-y1)/(x2-x1)
=(11-5)/(3-1)
=6/2
=3
Then use the line equation formula:
y=mx+c
You can substitute (1,5) if you like, also must substitute the slope as well!
5=3x1+c
c=2
Then find the full equation, which gives you the answer:
y=3x+2
Calculate for the mean/ average of the given numbers:
μ = (1 + 2 + 3 + 4 + 5) / 5 = 3
Then, we calculate for the summation of the squares of differences of these numbers from the mean, S
S = (1 - 3)² + (2 - 3)² + (3 - 3)² + (4 - 3)² + (5 - 3)²
S = 10
Divide this summation by the number of items and take the square root of the result to get the standard deviation.
SD = sqrt (10 / 5) = sqrt 2
SD = 1.41
Thus, the standard deviation of the given is equal to 1.41.
