Question

Is survey customers at the local shopping mall is belongs to random method?

Answer 1

No, you are not using a probability model for selecting your participants. This survey approach is using convenience sampling, and it is not random because only those interested by the survey will respond.

Answer 2

Which question is unbiased? Is soccer your favorite sports to watch? Or do you like calm, soothing ocean?

Answer 3

The first one. The 2nd one uses adjectives like calm/soothing which may bias people's response. If you just asked "Do you like the ocean.?" it is different from "Do you like the calm, soothing ocean.?" Calm/soothing have positive connotations and people are less likely to respond negatively when approached with such questions.

Answer 4

Julie's test grades were very consistent for six week grading period. Her grades 90,88,89,93,90. How the range of the data would support the teacher'S comment?

Answer 5

range = max value - min value
so here, range = 93 - 88 = 5. The range is 5, which is rather small considering you can potentially get grades from a wide range of 0 to 100. So the small range indicates that the grades are close to each other.

Answer 6

Thank you so much

Answer 7

:) your welcome

Answer 8

A factory produces 500,000 nails per day. Manager thinks that there are less then 2000 misshapen nails made per day. A random survey of 500 nails find 4 misshapen nails. Is the manager correct. Explain

Answer 9

Well you hope that the sample proportion is roughly the same as the population proportion.

At the population level: 2000/500,000 = 0.004

Sample level: 4/500 = 0.008

Now whether these 2 are significantly different.. not so sure. If you had an assumption of normality of the data, you could use a T-test or maybe some other significance test.

Answer 10

I am less familiar with non-parametric tests. But I am assuming this is probably not required? I'm assuming this is a beginners type of stats course?

Answer 11

Thank you. Please answer one more question. The city Of NY is considering shortening the length of the school day. Mr.A. Interviewed 54 student as they left the school. Is this random sample? Should the lengthy shool day which now 7 hr be shortened to 6?

Answer 12

Is this second question biased or fair?

Answer 13

This is definitely biased. He asked only students who are leaving the school. At that time of day, students are probably fed up with the day at school and are more likely to respond to shorten the day. I mean, you can imagine quite a few students not liking school, and even more so he asked while they were leaving.

Answer 14

And no the sample is not random. He specifically asked only students leaving the school, and the question at hand has to do when the length of school day