A is the correct answer !
Answer:
Step-by-step explanation:
The summary of the given data includes;
sample size for the first school 
= 42
sample size for the second school 
= 34
so 16 out of 42 i.e 
= 16 and 18 out of 34 i.e 
= 18 have ear infection.
the proportion of students with ear infection Is as follows:
= 0.38095
= 0.5294
Since this is a two tailed test , the null and the alternative hypothesis can be computed as :
level of significance ∝ = 0.05,
Using the table of standard normal distribution, the value of z that corresponds to the two-tailed probability 0.05 is 1.96. Thus, we will reject the null hypothesis if the value of the test statistics is less than -1.96 or more than 1.96.
The test statistics for the difference in proportion can be achieved by using a pooled sample proportion.
The pooled standard error can be computed by using the formula:
The test statistics is ;
z = - 1.368
Decision Rule: Since the test statistics is greater than the rejection region - 1.96 , we fail to reject the null hypothesis.
Conclusion: There is insufficient evidence to support the claim that a difference exists between the proportions of students who have ear infections at the two schools
Answer:
No, a convenience sample was taken.Therefore, the sample may not be representative of all college students in terms of number of hours studied per week.
Step-by-step explanation:
One of the important conditions required in other to estimate the mean of the population from the confidence interval. Requires that the data must be a random Sample. This is to ensure that sample values are not biased and as such are representative of the larger group of data.
However, in the scenario described above, the sample chose. Are friend's of the student, this makes the data lack randomness as those who aren't friends to the student do not stand a chance of being selected. The sampling procedure employed is called convenience sampling.
Answer:
Distance between A and B is 5400 meters
Step-by-step explanation:
Consider "D" the letter to identify distance between A and B
Let's use "t" to identify the time of the first encounter (Devi and Kumar), and create an equation that states that the distance covered by Devi (at 100 m/min) in time "t", is equal to the total distance D minus what Kumar has covered at his speed (80 m/min) in that same time:
Recall that distance equals the speed times the time:
distance= speed * time
First encounter:
100 * t = D - 80 * t
180 * t = D Equation (1)
Not, 6 minutes later (at time t+6) , Devi and Li Ting meet .
Then for this encounter the distance covered by Devi equals total distance d minus the distance covered by Li Ting:
100 *(t+6) = D - 75 * (t+6)
100 t + 600 = D - 75 t - 450
175 T + 150 = D Equation (2)
Now, let's equal equation (1) to equation (2), since D should be the same:
180 t = 175 t + 150
5 t = 150
t = 30
Then the time t (first encounter) is 30 minutes. Knowing this, we can use either equation to find D:
From Equation (1) for example: D = 180 * t = 180 * 30 = 5400 meters
<h3>
Answer: B) no solutions</h3>
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Explanation:
Let's isolate the variable y in the first equation
-2x - y = 1
-2x = 1 + y
1+y = -2x
y = -2x-1
Then we'll plug this into the second equation
-4x - 2y = -1
-4x - 2(-2x-1) = -1
-4x + 4x + 2 = -1
0x + 2 = -1
0 + 2 = -1
2 = -1
We run into a contradiction. No matter what x value we pick, the last equation will never be true. This leads to a domino effect to cause the first set of original equations to never be true when considered as a system.
Therefore, this system is inconsistent. There are no solutions. These two lines graph out parallel lines that never intersect.
