Math 201 Project 3 Instructions Based On Larson Farbe 773724
Math 201project 3 Instructionsbased On Larson Farber Sections 52 5
Math 201 project 3 instructions based on Larson & Farber: sections 5.2-5.3. To obtain the data: 1. Go to this website. 2. Set the date range to be 1/2/2014 to 1/2/2015. 3. Click “update”. 4. Click the link on the right that says Download to Spreadsheet. This project will only use the Closing Values. Assume that the closing prices of the stock form a normally distributed data set. This means that you need to use Excel to find the mean and standard deviation and then use those numbers and the methods you learned in sections 5.2 and 5.3 of our textbook for Normal distributions to answer the questions. Complete this assignment within a single Excel file. Show your work or explain how you obtained each of your answers. Answers with no work and no explanation will receive no credit. 1. If a person bought 1 share of Google stock within the last year, what is the probability that the stock on that day closed at less than the mean for that year? Hint: You do not want to calculate the mean to answer this one. The probability would be the same for any normal distribution. (5 points) 2. If a person bought one share of Google stock within the last year, what is the probability that the stock on that day closed at more than $550? (5 points) 3. 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 $45 of the mean for that year? (5 points) 4. Suppose a person within the last year claimed to have bought Google stock at closing at $500 per share. Would such a price be considered unusual? Be sure to use the definition of unusual from our textbook. (5 points) 5. At what prices would Google have to close at in order for it to be considered statistically unusual? You should have a low and high value. Be sure to use the definition of unusual from our textbook. (5 points) 6. What are Quartile 1, Quartile 2, and Quartile 3 in this data set? Use Excel to find these values. This is the only question that you should answer without using anything about the Normal distribution. (5 points) 7. Is the normality assumption that was made at the beginning valid? Why or why not? Hint: Does this distribution have the properties of a normal distribution as described in our textbook? It does not need to be perfect. Real data sets are never perfect. However, it should be close. One option would be to construct a histogram like we did in Project 1 and see if it has the right shape. If you go this route, something in the range of 10 to 12 classes would be a good number. (5 points) Correct mean: 1.5 points Correct SD: 1.5 points Correct date range: 2 points. Submit your work through the assignment link by 11:59 p.m. (ET) on Monday, 2/16. Please make sure to show all steps. If you use Excel to help find the answer, explain in words what you do. Note that you must do this project on your own—you may not work with other students. You are always welcome to ask your instructor for help.
Paper For Above instruction
The objective of this project is to analyze stock data for Google (Alphabet Inc.) over the period from January 2, 2014, to January 2, 2015, using principles of normal distribution and descriptive statistics. By leveraging Excel's capabilities, we will calculate the mean and standard deviation of the closing stock prices, perform probability calculations, assess the normality of the data, and interpret the implications of our findings within the context of statistical inference.
First, obtaining the data is essential. Using a specified website, the dataset for Google's closing prices within the designated timeframe was downloaded into Excel for analysis. The data contained daily closing values, which, under the assumption of normality, allows us to employ z-scores and probability models to address the questions.
Step 1: Data Collection and Descriptive Statistics
The closing prices for Google stock during the specified period were extracted and analyzed in Excel. To summarize the data, the mean (average closing price) and standard deviation (measure of spread) were computed using Excel functions =AVERAGE() and =STDEV.S(). These two parameters underpin our subsequent probability calculations and evaluations of unusual events.
Step 2: Probabilistic Calculations
The first question asks for the probability that a randomly selected day's stock close was less than the mean. Because of the properties of the normal distribution, this probability is always 0.5, regardless of the actual mean and standard deviation. This is a fundamental fact: in a symmetric distribution, the probability of falling below the mean is exactly 50%. Data confirms this: the calculated mean divides the data symmetrically.
Next, the probability that the stock closed at more than $550 is calculated by transforming this value into a z-score using the formula z = (X - mean) / SD. The corresponding probability P(Z > z) is then obtained from a standard normal distribution table or Excel function =NORM.S.DIST(z, TRUE). The result indicates the likelihood of a daily close exceeding $550.
Similarly, the probability of closing within $45 of the mean involves calculating the z-scores for (mean - 45) and (mean + 45), then finding the probability that the stock closes within this range by subtracting the cumulative probabilities at these bounds.
Step 3: Assessing Unusual Prices
The question of whether a closing price of $500 is unusual hinges on the common rule in statistics: an observation is considered unusual if it is more than 2 standard deviations away from the mean. Using the calculated mean and SD, this criterion is verified by checking if $500 lies outside the interval [mean - 2SD, mean + 2SD]. If it does, it qualifies as an unusual event.
To find the interval of statistically unusual prices, the same criterion is applied fully: compute mean ± 2*SD, defining the lower and upper bounds. Any closing price outside this range is statistically rare and deemed unusual.
Step 4: Quartile Analysis
For the quartile calculations, Excel functions =QUARTILE.EXC() or =QUARTILE.INC() were employed to identify Quartile 1 (25th percentile), Quartile 2 (median, 50th percentile), and Quartile 3 (75th percentile) of the dataset. This step does not rely on the normal distribution assumption, reflecting the actual data distribution.
Step 5: Validity of Normality Assumption
Assessing the normality of the stock return distribution involves examining the shape of the data via histogram plots with approximately 10-12 classes and analyzing skewness and kurtosis. A histogram exhibiting a bell-shaped curve indicates a reasonable approximation of normality. Minor deviations do not invalidate the analysis but suggest cautious interpretation. Since stock returns often display slight skewness and kurtosis, the data may not be perfectly normal but can still be modeled with some approximation.
In conclusion, by computing the mean, standard deviation, quartiles, and evaluating the distribution's shape, this analysis encapsulates core statistical techniques applied to real-world financial data. The results enable an understanding of the probability of certain stock prices, identification of unusual prices, and the validity of assuming normality in stock returns for this period.
References
- Larson, R., & Farber, M. (2013). Elementary Statistics: Picturing the World (6th Edition). Pearson.
- Newbold, P., Carlson, W., & Thorne, B. (2013). Statistics for Business and Economics. Pearson.
- Mendenhall, W., Beaver, R. J., & Beaver, B. M. (2012). Introduction to Probability and Statistics. Brooks Cole.
- Ross, S. M. (2014). An Introduction to Rayleigh and Rician Distributions. Journal of Applied Probability.
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