Answer:
b. The student's scores on the posttest would have a smaller standard deviation.
Step-by-step explanation:
The first test is taken before the material is covered in class so we expect the standard deviation to be high because not everyone's scores would be lying close to the mean. Equal number of students mastered most, some or almost none of the material from reading the textbook based on the pretest result. this means the data is varying, so the standard deviation is large.
Whereas, after the teacher has taught the material and given the homework, they must have understood most of the material. The test they take after teaching as a post test. The results of the post test would have a smaller standard deviation as most of the students would have scored good. Hence, the student's scores on the posttest would have a smaller standard deviation.
Answer:
A
I took a picture of your mom and my phone ran out of storage.
4 + 12 +12 = 28cm
so in conclusion it is 28
Answer:
Step-by-step explanation:
We are given the following in the question:
The needle size should not be too big and too small.
The diameter of the needle should be 1.65 mm.
We design the null and the alternate hypothesis
Sample size, n = 35
Sample mean, 
= 1.64 mm
Sample standard deviation, s = 0.07 mm
Type I error:
- It is the error of rejecting the null hypothesis when it is true.
- It is also known as false positive error.
- It is the rejecting of a true null hypothesis.
Thus, type I error in this study would mean we reject the null hypothesis that the average diameter is 1.65 mm but actually the average diameters of the needle is 1.65 mm.
Thus, average diameter is 1.65 mm and we decide that it is not 1.65 mm.
