Stocks, Retail, And Utility: How Profitable Are Different Se
Stocks Retail And Utility How Profi Table Are Different Sectors Of Th
Stocks: Retail and Utility How profi table are different sectors of the stock market? One way to answer such a question is to examine profi t as a percentage of stockholder equity. A random sample of 32 retail stocks such as Toys “R” Us, Best Buy, and Gap was studied for x1, profi t as a percentage of stockholder equity. The result was x1 = 13.7. A random sample of 34 utility (gas and electric) stocks such as Boston Edison, Wisconsin Energy, and Texas Utilities was studied for x2, profi t as a percentage of stockholder equity. The result was x2 = 10.1 (Source: Fortune 500, Vol. 135, No. 8). Assume s1 = 4.1 and s2 = 2.7.
(a) Let m1 represent the population mean profi t as a percentage of stockholder equity for retail stocks, and let m2 represent the population mean profi t as a percentage of stockholder equity for utility stocks. Find a 95% confidence interval for m1 – m2. Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all positive, all negative, or of different signs? At the 95% level of confidence, does it appear that the profi t as a percentage of stockholder equity for retail stocks is higher than that for utility stocks?
Paper For Above instruction
The profitability of different sectors within the stock market can provide valuable insights for investors seeking optimal returns. This study compares the sector-specific profits, measured as a percentage of stockholder equity, for retail and utility stocks. The primary goal is to determine whether there is a statistically significant difference in the average profitability between these two sectors through the calculation of a confidence interval and hypothesis testing.
Introduction
The retail and utility sectors represent distinct categories within the stock market, each influenced by different economic factors. Retail stocks, driven by consumer spending, typically exhibit higher volatility but potentially higher profitability. In contrast, utility stocks, often regarded as stable and dividend-yielding investments, tend to have lower profit margins relative to equity. Understanding whether these sectors differ significantly in profitability can inform portfolio diversification strategies and sector allocation decisions. This analysis employs statistical methods to compare the mean profits, focusing on the difference in sector performance through confidence intervals and hypothesis testing.
Methodology
The study utilizes sample data from two sectors. For retail stocks, a sample of 32 stocks yielded an average profit percentage (x1) of 13.7 with a known standard deviation s1= 4.1. For utility stocks, a sample of 34 stocks resulted in an average profit percentage (x2) of 10.1 with a standard deviation s2= 2.7. The samples are assumed to be independent and representative of their respective sectors. We aim to estimate the true difference in population means (m1 – m2) through a two-sample t-interval, considering the sample statistics and standard errors.
Results and Interpretation
To compute the 95% confidence interval for the difference in means (m1 – m2), we first determine the standard error (SE):
SE = sqrt( (s1^2 / n1) + (s2^2 / n2) ) = sqrt( (4.1^2 / 32) + (2.7^2 / 34) )
Calculating each term: (4.1^2) / 32 ≈ 0.525, and (2.7^2) / 34 ≈ 0.214. So, SE ≈ sqrt(0.525 + 0.214) ≈ sqrt(0.739) ≈ 0.86.
The degrees of freedom for this t-interval are approximated using the Welch-Satterthwaite equation, leading to approximately 61 degrees of freedom. The critical t-value for 95% confidence and df ≈ 61 is about 2.000.
The margin of error (ME):
ME = t_{0.025, df} SE ≈ 2.000 0.86 ≈ 1.72.
The difference in sample means is:
x1 – x2 = 13.7 – 10.1 = 3.6.
Thus, the 95% confidence interval is:
(3.6 – 1.72, 3.6 + 1.72) = (1.88, 5.32).
Interpretation:
The confidence interval suggests that, with 95% confidence, the true difference in average profits as a percentage of stockholder equity between retail and utility stocks lies between approximately 1.88% and 5.32%. Since the entire interval is positive, it indicates that retail stocks, on average, have a higher profit relative to stockholder equity than utility stocks.
Implications of the Results
The positive entire confidence interval implies a statistically significant difference favoring retail stocks. This finding aligns with the general understanding that retail companies, driven by consumer market dynamics, often demonstrate higher profit margins. Utility companies, known for their stability and regulated profits, tend to maintain lower but steadier profit levels. The analysis confirms that, at the 95% confidence level, retail stocks outperform utility stocks in terms of profit margins relative to equity.
Further Analysis: Hypothesis Testing
To complement the confidence interval, a two-sample t-test is performed at an alpha level of 0.01 to examine whether retail stocks have significantly higher profits compared to utility stocks. The null hypothesis (H0): m1 – m2 ≤ 0, and the alternative hypothesis (H1): m1 – m2 > 0. Calculating the t-statistic:
t = (x1 – x2) / SE = 3.6 / 0.86 ≈ 4.19.
Comparing this to the critical t-value for 0.01 significance level and df ≈ 61, which is approximately 2.66. Since 4.19 > 2.66, we reject the null hypothesis, providing strong evidence that retail stocks indeed have higher profit margins than utility stocks.
Conclusion
The statistical analysis, through both confidence interval estimation and hypothesis testing, indicates a significant difference in profitability between retail and utility sectors, favoring retail. This insight can inform investors considering sector-specific investments, highlighting the higher profit potential in retail stocks relative to utility stocks. However, it is also essential to consider other factors such as sector stability, growth potential, and market conditions when making investment decisions.
References
- Fortune 500. (Year). Fortune 500, Vol. 135, No. 8.
- Newbold, P., Carlson, W. L., & Thorne, B. (2013). Statistics for Business and Economics. Pearson.
- Devore, J. L. (2015). Probability and Statistics for Engineering and the Sciences. Cengage Learning.
- Moore, D. S., & McCabe, G. P. (2014). Introduction to the Practice of Statistics. W.H. Freeman.
- Wooldridge, J. M. (2013). Introductory Econometrics: A Modern Approach. Cengage Learning.
- Lehmann, E. L., & Casella, G. (1998). Theory of Point Estimation. Springer.
- Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences. Lawrence Erlbaum Associates.
- Ruscio, J., & Manna, A. (2017). Statistical analysis using confidence intervals. Journal of Data Science.
- Levin, R. I., & Rubin, D. S. (2007). Statistics for Management. Pearson.
- Kirk, R. E. (2013). Experimental Design: Procedures for the Behavioral Sciences. SAGE Publications.