31 Questions

QUESTION 1 of 31

A bag contains 50 names in it. A professor plans to draw three names from the bag to win a free
graphing calculator. How many different sets of three winners can be drawn from the bag?

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QUESTION 2 of 31

1. Test the claim that the standard deviation of the number of aircraft stolen each year in the US is less than 15 if a sample of 12 years had a standard deviation of 13.6. use @=0.05.

2. A film editor feels that the standard deviation for the number of minutes in a video is 3.4 minutes. A sample of 24 videos has a standard deviation of 4.2 minutes. At @=0.05,is the samples standard deviation different from what the editor hypothesized?

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QUESTION 3 of 31

I need to run a t-test and/or ANOVA to determine the following:
1. was there weight loss as a result of overall diet programs?
2. Was there any difference between males and females in this regard
3. Were there differences between diet programs in terms of their impact on weight loss. Which program was best for losing weight.
I have the SPSS data file that took 3 types of diet programs. I am confused what tests to run and how.

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QUESTION 4 of 31

Hello professor, I am going over Problem 6 of 8.4 and I don't get why when looking for the P value you added? I'm following Problem 1 and thought I had to subtract for P value. Thank you!

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QUESTION 5 of 31

15. A doctor claims that the proportion of Americans exercising the recommended minimum of 45 minutes per day is less than ten percent. A sample of 550 Americans reveals that 52 of them exercise at least 45 minutes per day. At the 10% significance level test the doctor's claim.

For some reason I can't watch any of the videos. I tried going on Google Chrome and Internet Explorer, but none of them are playing the video on how to solve this problem.

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QUESTION 6 of 31

If a person bought 1 share of Google stock within the last year, what is the probability that the stock on that day closed within $50 of the mean for that year (round to two places)? (Hint: this means the probability of being between 50 below and 50 above the mean). I cannot figure out the formula for this.. please help:)

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QUESTION 7 of 31

This is a general question about sample variance. What is a degree of freedom? The reference page given in my Stat textbook doesn't mention it by name, and could not find it here. Thanks so much!

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QUESTION 8 of 31

Chapter 8.2, Problem 7: I noticed for the other problems, we did the opposite or alternative for each value. Ho to Ha. How come we didn't do the alternative one for problem 7?

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QUESTION 9 of 31

30. The following Minitab display was created from speed data collected on a strip of I-95 where the
speed limit is posted as 55mph. Use the Minitab display below to identify the point estimate for
the population mean, and interpret the 95% confidence interval provided by Minitab.

I am not sure how this went completely over my head and i know the answer is in my face. can you shed some light on this please professor.

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QUESTION 10 of 31

hi professor, im having some trouble with a binomial random variable question and I was hoping that you could clarify. the problem is as follows P(170 less than equal to x less than 180) when n = 600 p = .3 I know that the mean is 180 and the standard dev. is 11.2249
but is it as simple as just finding the area from 170 to the mean or am I over simplifying ?

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QUESTION 11 of 31

Professor I section 7.3 question number 3
A child psychologist wants to estimate the time it takes a child to respond to a question
with a lie while playing the video game Tetris. If the researcher wants to estimate the
average time to respond within a margin of error of 0.10 seconds, and he wants to use
98% confidence, how many children does he have to time while they attempt to
respond with a lie? Assume the standard deviation of response times is 0.6 seconds.

i got 196 children
i used 2.33 for Z is that where i got it wrong ?

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QUESTION 12 of 31

Hi Professor,

I need help with exercise #13 letter b from the homework for chapter 6. I don't understand how to get 0.0001 given the fact that the Z scores couldn't be found in the Z table. Please help!

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QUESTION 13 of 31

Hi Professor!

I keep getting this question wrong please help. A bag contains 15 yellow marbles, 10 red marbles, and 5 white marbles. The marbles are identical except for their colors. What is the probability that when three marbles are selected without replacement that one of them is white. How could I know that just one is going to come out to be white????

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QUESTION 14 of 31

3. A cable company in Tallahassee claims that at least 90 percent of customers are very satisfied with the service they receive. To test this claim, the local newspaper surveyed 150 customers, using simple random sampling. Among the sampled customers, 132 reported they are very satisfied. Based on these findings, is the cable company's claim valid? Use a 0.05 level of significance.
[Hint: Conduct a Test of Hypothesis for a Sample Proportion] (5 points)


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QUESTION 15 of 31

Hello Professor, the question is in regards to completing an ANOVA table for a two factorial experiment, I understand certain elements to generating values but I am wondering if you can answer this question that was given to me in my course that didn't give much of an explanation on how certain parts were done. Thank You.

a) give the numbers of levels of each factor
b)Complete the ANOVA Table
c) Test to determine whether treatment means differ? using alpha .10
d) Conduct a test of factor interact and mean effects, each at .10 alpha level of significance.

Sources of Variation SS DF MS F
A 3 .75
B .95 1
AB .30
Total 6.5 23

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QUESTION 16 of 31

Good Afternoon professor... I also have another question... in Wilsons adjustment for estimating p.. the formula of P: x+2/n+4... what does x stand for? what value is it?

Thank you very much,


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QUESTION 17 of 31

Good Afternoon Mr. McGuckian,

I am not very sure when to use Wilson's adjustment for estimating p method for chapter 7. I know that it is used when p is close to 0 or 1... but what I don't know is, how close? where do I draw the line between "p" values that are way to close to 0 or 1 over the ones that are close but in which the normal sample proportion can be used?

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QUESTION 18 of 31

Hi professor, I am not getting a question number 70 from mixed review of chapter 7? Like what should be the ^p?

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QUESTION 19 of 31

Hello professor, where can I find the formula sheet for exam1?

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QUESTION 20 of 31

Hello Professor, I really don't understand this question

62. If you wanted to determine the number of people needed for a survey to determine the percent of the population without health insurance, how could this be done? Assume you would like to ultimately form a 95% confidence interval with a margin of error of just 2 percentage points (hint: think of the margin of error formula for the proportion interval).

I really don't know how I would actually go about this. I read the answer and I still don't understand what values you would even plug into the equation for p hat and q hat.

Can you please help, thank you for your time.

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QUESTION 21 of 31

(This is in my H.W 9.1 Testing the Differences Between Two Means: Using z Test)
Teachers' Salaries: California and New York lead the list of average teachers' salaries. The California yearly average is $64,421 while teachers in New York make an average annual salary of $62,332. Random samples of 45 teachers from each state yielded the following:

-Sample Mean = 64,510
-Population Standard Deviation=8,200

New York:
-Sample Mean= 62,900
-Population Standard Deviation= 7,800

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QUESTION 22 of 31

Hello Professor,

In the homework for chapter 5, number 40 asks "The fastest finishing times for the NY marathon are normally distributed with a mean of 147.08 minutes and a standard deviation of 1.48 minutes. Find the finishing time for the slowest 4% of winning NY marathon runners."
After viewing the answer, it seems that the bell curve was cut at the 4% on the right side of the curve. I'm still confused as to why we wouldn't cut it on the left side (making the z-score negative) since it is asking for the slowest 4%?

Thank you!
Sofia Novo

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QUESTION 23 of 31

Good Afternoon Mr. McGuckian,

I am reading Chapter 7.4 and in the part that says recall, I don't understand very well what the signs stands for or what it is trying to say.

I am referring to this part:

Recall: The CLT says if X ~ N(u,o^2 ), then X ~ N(u,o^2/n) for any sample size n—no matter how small.

I know we are talking about when to use the t-distribution and when not to use it (you use t when n is less than 30).. but I like to understand everything that is written on the notes... and I know the answer is probably super easy and that's why its embarrassing to ask.. but I would rather make sure I understand everything well.

Thank You Very Much
Adriana Nava

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QUESTION 24 of 31

Professor, for number 12 on homework section 5.1 P

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QUESTION 25 of 31

professor, for #14 in the 9.3 section of the hw, what do you do if the degree of freedom is not on the t-table. for example, the degree of freedom for that problem is 52 but it is not on the table. Thank you!

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QUESTION 26 of 31

Professor I just have a question about the test. On class you said you would give us some bonus questions in order to give us a chance of a better grade. How many, if any question would be considered bonus questions. Thanks for your time.

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QUESTION 27 of 31

I am sorry I keep asking questions, I am just a bit confused when it comes to the exam's formula cards. In class you said we could add some information to it, however I am not sure what you meant by that. Is it okay if I add steps on how to get class boundaries and width? And in your opinion, how much is too much? Thank you so much for your time, and sorry for the bother.

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QUESTION 28 of 31

When doing stem and leaf plots, if there is two or more of the same number, how do you graph it?

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QUESTION 29 of 31

Hi Professor,
I'm having trouble with question 2 from the Now You Try it problems in section 7.2
I found my Z to be .04
When I calculated E I got 1.31 as my result so when finding my two intervals I got 319.7 and 317.08, but it is wrong.
Could you tell me what I did wrong?

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QUESTION 30 of 31

Hello professor,
on 10.1 "Do It Yourself!" problem 1 i noticed that mmy calculator does not round as exact as your answers but im doing all the work properly and in the correct steps. I have a scientific calculator but not graphing calculator will you calculate these differences on the third exam? for example for the SSE on that particular problem my answer was: 2075910.519 while on the given answer it stated 2,075,911.429

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QUESTION 31 of 31

I know that for a sample size to be valid it must be over

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