Introduction to the Practice of Statistics Essay

1. Suppose a researcher wants to design a new study with a power of 0.8 and a significance of 0.05 to test whether the caffeine content for a brand of coffee is really 100mg. A previous study gave a mean caffeine level for this brand of 110 mg and a standard deviation of 7 mg. Use PROC POWER to determine how many cups of coffee need testing.

Due to financial hardship, the Nyke shoe company feels they only need to make one size of shoes, regardless of gender or height. They have collected data on gender, shoe size, and height and have asked you to tell them if they can change their business model to include only one size of shoes – regardless of height or gender of the wearer. In no more 5-10 pages (including figures), explain your recommendations, using statistical evidence to support your findings. The data found are below:

(1) A study of the number of cars sold looked at the number of cars sold at 500

Sampling distribution of a sample statistics is the hypothetical distribution of the sample statistics of interest for a random sample, whereas the distribution of a sample is the probabilistic distribution of the ideas in the sample. The sampling distribution indicates how likely it is to get some definite sample when one draws a large amount of samples and the distribution of a sample shows how possible it is to get a particular data in a single random

Assuming unequal variances, the two sampled t-Test was applied on the data sets of female and male shoe sizes with the alpha value of 0.05. The null hypothesis was that the female and male shoe sizes have an equal mean while the alternative hypothesis was that female and male shoe sizes do not have an equal mean. With the degrees of freedom being 27, the t-statistic is -8.16. The probability that -8.16 is ≤ -1.70 is 4.5×10-9 for the one-tailed test. Also, the probability that -8.16 is ≤ ±2.05. is 9.1×10-9 for the two-tailed test. Given that both probabilities are under the alpha value of 0.05, the null hypothesis is therefore rejected, and the alternative hypothesis is accepted at the 95% confidence level.

AP Statistics is a great start to further your education in a math-related field. As this class will look impressive on your transcript and there is a possibility of college credit if you score well enough on the AP exam with accords to your college choice standards. The course will provide an in-depth overview of exploring data, sampling and experimentation, anticipating patterns, and statistical inference. You will study statistics and apply it to intricate problems.

c. What kind of display would you use to show the association between job class and mode of

A theory often used in the research of individual health behavior and behavioral intentions is the theory of planned behavior (Ajzen, 1991). According to this theory, the performance of any behavior depends on behavioral intention. Behavioral intention is viewed as being dependent on behavioral beliefs (e.g., attitude towards the behavior), normative beliefs, and control beliefs. Normative beliefs are beliefs about the expectations of others, and control beliefs are beliefs about the factors that may help or hinder the performance of the behavior. The framework for the study of physical activity discussed earlier by Armitage (2005) is based on this theory. That study found that behavioral beliefs, normative beliefs, and control beliefs all contribute to physical activity behavior.

the correlation is 0.668; the equation of regression is CREDITS=11.7475*AGE-174.356; the slope is 11.7475 which is positive; when the predictor variable AGE increase, the response variable CREDITS also strongly increase; for instance, when AGE increase by 1, the CREDITS will increase 11.7475. There are some outliers may affect the correlation. Based on the graphs and data above, we can find out a student who is older with a litter lower GPA, but has very higher credits; the student with higher credits also has high GPA.

A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Using   = .05, what is the value the test statistic?

of the same interest that is measured at the same time, where one person has received

-The sampling distribution is a distribution of the results if all possible samples are selected, where as a population distribution is the distribution of a particular variable of interest.

Major League Baseball is known as America’s favorite pastime, and MLB teams spend an extensive amount of money in the excess of a billion dollars with the ultimate goal to win the World Series. This learning team’s focus throughout this descriptive statistics paper is the MLB players’ performances, salaries, salary caps, and winning percentages. Though salaries will by no means be a trade for wins, the goal is to use the less experienced players and pay them a lower salary. Research has been done on whether or not player’s salaries and wins are connected.

I first discovered my interest in statistics in my sophomore year at the University of California, Berkeley. In a statistics lecture, the professor explained how statistics can be applied in real life by giving an example that Amazon often promotes products by emailing its customers and recommending products according to sophisticated analysis of customers’ search records, as well as their transaction data. Previously having been immersed in the world of abstract statistics, I realized that in addition to being an essential tool to confirm theories already proposed, data itself can lead to entirely new ideas. The data patterns can be interpreted from many different perspectives, which triggered my eagerness to explore the stories hidden in data and improve my understanding of the world through data analysis.

The objective of this chapter is to describe the procedures used in the analysis of the data and present the main findings. It also presents the different tests performed to help choose the appropriate model for the study. The chapter concludes by providing thorough statistical interpretation of the findings.