based on last 3 lectures, please reply to these 6 comments!

1)

Benny

Part One - Confidence Intervals

"A confidence interval is simply a range of values that could contain the actual population parameter of interest.It is centered on the sample mean, and uses the variation in the sample to estimate a range of possible values." (Lind, Marchel, & Wathen, 2008) A single point estimate uses sample data but it is considered like a best guess and is hard to determine and they are subject to biases.When speaking with the Manager he told me that he prefers a confidence interval to a single point estimate because he can get more accurate information with real time answers and he does not have to play the guessing game. "Confidence intervals often provide the added information and comfort about estimates of population parameter values that the single point estimates lack." (Lind, Marchel, & Wathen, 2008) Confidence intervals provide information about a range in which the true value lies with a certain degree of probability, as well as about the direction and strength of the demonstrated effect. This helps when it comes to asking parents at our school to vote on some of the curriculum that will be taught.We just took a poll to see what foreign language will be part of the curriculum for the nest fiscal year.Since the population is 85 % Mexican and already speak Spanish they will be adopting a native language book. We still have that 15% that is non-Spanish speak and are trying to learn a foreign language so they will be offering French and Chinese based off of the voting results.

Part Two - Chi Square

A chi square test is very similar to a t-test because you have to do null hypotheses and alternative hypotheses. The null hypothesis is what is assumed to be true until we have evidence to go against it. "The Chi Square test compares the actual versus a proposed distribution of counts by generating a measure for each cell or count: (actual - expected)2/actual." (Lind, Marchel, & Wathen, 2008) This test helps us understand that the equal pay a little bit more because it is comparing actual range and expected range.I believe it reinforces my decision from last week because we are still not comparing all the data that is given and we are only comparing 50 employees not the whole company.Taking my example of the voting for the foreign language if we were to put it on a spread sheet we would have real results.This would help the school district in deciding if it would be beneficial to have classes for Spanish for both native and non-native language as a school adoption.

Part Three - Overall Reactions

Before taking this statistic class, I did not realize that I was using it every day to make decision. In my professional life I use excel spreadsheets to make decisions on which vendor gives us more for our money. We do not actually use the t-testing, f-testing or ANOVA testing but it does seem like I use more of the Chi square testing.It will help me in my business career through traveling to collect data in various types of enterprises and get to know how various businesses operate. It will also give me a hand in overseeing an industry survey design and its implementation hence helping in making decision before perpetrating an action in the real field.

2)

Cherly

Part One - Confidence Intervals

A confidence interval is a range around a measurement that conveys how precise the measurement is. Single point estimates are that a single point. Using confidence interval is from a range of values (interval) that act as good estimates of the unknownpopulation parameter

.

Part Two - Chi Square

Chi-squared tests are often constructed from asum of squared errors

, or through thesample variance

. Test statistics that follow a chi-squared distribution arise from an assumption of independent normally distributed data, which is valid in many cases due to thecentral limit theorem

. A chi-squared test can be used to attempt rejection of the null hypothesis that the data are independent. The chi-square test allows us to find the similarity distributions between two samples. You could use chi-squared to determine if certain types of products sell better in certain geographic areas. Is gender a factor in color preference of a car?

Part Three - Overall Reactions

Yes, my opinion has changed; I have a much great respect for statisticians. This has been a very challenging class. In my career, I think I will think of my analytical work in a different view point instead of just focusing on the numbers.

3)

Sherry

Part One - Confidence Intervals

A confidence interval is a range of values that we expect to contain the actual population mean based on the sample results we obtained. (Lind, Marchel, & Wathen, 2008).Some prefer them to a single point estimate because they often provide the added information and comfort about estimates.Because we do not use them a lot, my manager does not have a particular one to use.I would use the confidence interval because it would provide the added information that I may need.

One of the strengths of using confidence intervals in making decisions is that you can use several pieces of information from the sample.One weakness that I think is that you still do not have all the information from the samples.You are only using parts of it.Sometimes the estimates when using confidence intervals may be out of range causing the incorrect figures or results.

Part Two - Chi Square

The Chi Square family of tests looks at patterns within samples and sees whether the underlying populations could contain the same pattern of measure distributions (Lind, Marchel, & Wathen, 2008).A Chi Square test can sometimes be used to reject the null hypothesis.A Chi Square test allows one to find the similarity distributions between two samples.

Part Three - Overall Reactions

Has your opinion about statistics changed? How can statistical analysis help your professional career? (This should be completed by Day 5.)

My opinion about statistics have drastically changed since the beginning of this course.I have learned of several different tests that can be performed on the same samples in order to receive different results.Although it has been a struggle, I think I may incorporate statistics in my work habits.

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4)

Cherly

Chi-square tests are great to show if distributions differ or if two variables interact in producing outcomes.What are some examples of variables that you might want to check using the chi-square tests?

"The chi-square test of independence, or r k chi-square is a test of the independence of two nominal scale variables" (Tanner, D. E., & Youssef-Morgan, C. M. 2013).Some examples of variables that I might want to check using the chi-square test would be the count of categories.A chi-square test could be used during voting season.Voters could be categorized by male or female, their political preference or even their age range.

What would these results tell you?

These results could tell us if the political preference has something to do with the gender or age of the voters.

5)

Benny

At times we can generate a regression equation to explain outcomes.For example, an employee's salary can often be explained by their pay grade, appraisal rating, education level, etc.What variables might explain or predict an outcome in your department or life?If you generated a regression equation, how would you interpret it and the residuals from it?

We employ recruiters (consultants) who focus on implementation of our financial software program in order to earn commissions on sales revenue resulting from gaining them as clients. The more clientswe have, the more sales revenue and profit is made for the company. One of the most detrimental factors to profitability is the high turnover in the recruiter positions. There are a number of variables that might predict this turnover, such as years of experience, job satisfaction and appraisal rating. There are also some more interesting variables that seem to be correlated to the turnover such as the rate of success in the first year of recruiting for the company. It seems that it can take up to two years in order for a recruiter to get enough traction, so to speak, to become high earners. There is also a great deal of pressure to hit goals such as telephone talk time and on-boardingx number of new candidates within certain time frames.The regression equation could be generated in order to predict how long a recruiter might continue working for the company based on the known independent variables. Management can then more adeptly predict the amount of turnover and work toward keeping sales revenue from waning due to unexpected turnover.This could be through better retention practices and hiring procedures. When certain independent variables prove to have little or no correlation to the turnover, these residuals can be further studied in order to identify what other factors or variables might be affecting the turnover.

6)

Sherry

Which test is the least likely to perform?I think for me the Chi Square test would be the leaset likely one that I would use because I would not want or need to know some of the patterns involved in performing it.With the type of people that I work with, all they want to know is a quick answer without all the details.