 Recent questions in Bivariate numerical data
College StatisticsOpen question THABISILE MOTA2022-05-29

## The average credit card debt for a recent year was $9205. Five years earlier the average credit carddebt was$6618. Assume sample sizes of 35 were used and the population standard deviations ofboth samples were $1928. Find the 95% confidence interval of the difference in means. College StatisticsAnswered question ## J. P. Morgan Asset Management publishes information about financial investments. Between 2002 and 2011 the expected return for the S&P was with a standard deviation of and the expected return over that same period for a Core Bonds fund was with a standard deviation of (J. P. Morgan Asset Management, Guide to the Markets). The publication also reported that the correlation between the S&P and Core Bonds is . You are considering portfolio investments that are composed of an S&P index fund and a Core Bonds fund. a. Using the information provided, determine the covariance between the S&P and Core Bonds. Round your answer to two decimal places. If required enter negative values as negative numbers. College StatisticsOpen question Njifor Raymond2022-03-18 ## the probability that a mash stick will break on been stroked is 0.4.what is the probability that out of 50 sticks striken a) non will breakb)more than one stick will break College StatisticsAnswered question Charles Kingsley 2021-12-17 ## Give an example of each or state that the request is impossible. For any that are impossible, give a compelling argument for why that is the case. a) A sequence with an infinite number of ones that does not converge to one. b) A sequence with an infinite number of ones that converges to a limit not equal to one. c) A divergent sequence such that for every $n\in N$ it is possible to find nn consecutive ones somewhere in the sequence. College StatisticsAnswered question aortiH 2021-06-29 ## For all these problems, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. In order to use a normal distribution to compute confidence intervals for p, what conditions on pp and nq need to be satisfied? College StatisticsAnswered question Elleanor Mckenzie 2021-06-23 ## The pathogen Phytophthora capsici causes bell pepper plants to wilt and die. A research project was designed to study the effect of soil water content and the spread of the disease in fields of bell peppers. It is thought that too much water helps spread the disease. The fields were divided into rows and quadrants. The soil water content (percent of water by volume of soil) was determined for each plot. An important first step in such a research project is to give a statistical description of the data. Soil Water Content for Bell Pepper Study 1591510amp;14amp;15amp;12amp;10amp;14amp;12amp;9amp;10amp;14amp;9amp;10amp;11amp;13amp;10amp;9amp;9amp;12amp;7amp;9amp;amp;11amp;14amp;16amp;amp;11amp;13amp;16amp;amp;11amp;14amp;12amp;amp;11amp;8amp;10amp;amp;10amp;9amp;11amp;amp;11amp;8amp;11amp;amp;13amp;11amp;12amp;amp;16amp;13amp;15amp;amp;10amp;13amp;6 (a) Make a box-and-whisker plot of the data. Find the interquartile range. College StatisticsAnswered question illusiia 2021-06-23 ## You were asked about advantages of using box plots and dot plots to describe and compare distributions of scores. Do you think the advantages you found would exist not only for these data, but for numerical data in general? Explain. College StatisticsAnswered question glasskerfu 2021-06-19 ## Use a graphing calculator to construct a 95% confidence interval for a sample of size 30 from a uniform distribution over the interval (0, 1). Take a class poll to determine the percentage of confidence intervals that contain the true mean. Discuss the result in class. College StatisticsAnswered question jernplate8 2021-06-19 ## Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. In a survey of 2241 U.S. adults in a recent year, 650 made a New Year's resolution to eat healthier. College StatisticsAnswered question facas9 2021-06-08 ## When a correlation value is reported in research journals, there often is not an accompanying scatterplot. Explain why reported correlation values should be supported with either a scatterplot or a description of the scatterplot. College StatisticsAnswered question emancipezN 2021-06-03 ## Suppose you were to collect data for each pair of variables. You want to make a scatterplot. Which variable would you use as the explanatory variable and which as the response variable? Why? What would you expect to see in the scatterplot? Discuss the likely direction, form, and strength. Gasoline: number of miles you drove since filling up, gallons remaining in your tank College StatisticsAnswered question banganX 2021-05-31 ## Driven by technological advances and financial pressures, the number of surgeries performed in physicians' offices nationwide has been increasing over the years. The function $f\left(t\right)=-0.00447{t}^{3}+0.09864{t}^{2}+0.05192t+0.8\left(0\le t\le 15\right)$ gives the number of surgeries (in millions) performed in physicians' offices in year t, with $t=0$ corresponding to the beginning of 1986. a. Plot the graph of f in the viewing window $\left[0,15\right]×\left[0,10\right]$. b. Prove that f is increasing on the interval [0, 15]. College StatisticsAnswered question Phoebe 2021-05-08 ## You are given the sample mean and the population standard deviation. Use this information to construct 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. From a random sample of 24 months from January 2006 through December 2016, the mean number of tornadoes per month in the United States was about 100. Assume the population standard deviation is 114. College StatisticsAnswered question boitshupoO 2021-05-05 ## Consider a random sample of size n = 31, with sample mean $\stackrel{―}{x}=45.2$ and sample standard deviation s = 5.3. Compute 90%, 95%, and 99% confidence intervals for \muμ using Method 1 with a Student's t distribution. Round endpoints to two digits after the decimal. College StatisticsAnswered question alesterp 2021-05-05 ## The following advanced exercise use a generalized ratio test to determine convergence of some series that arise in particular applications, including the ratio and root test, are not powerful enough to determine their convergence. The test states that if$\$ $lim\left\{n\to \mathrm{\infty }\right\}\frac{a\left\{2n\right\}}{{a}_{n}}<\frac{1}{2}$ then $\sum {a}_{n}$converges,while if $lim\left\{n\to \mathrm{\infty }\right\}\frac{a\left\{2n+1\right\}}{{a}_{n}}>\frac{1}{2}$, then $\sum {a}_{n}$ diverges. Let ${a}_{n}=\frac{1}{1+x}\frac{2}{2+x}\dots \frac{n}{n+x}\frac{1}{n}=\frac{\left(n-1\right)!}{\left(1+x\right)\left(2+x\right)\dots \left(n+x\right)}$. Show that $\frac{{a}_{2n}}{{a}_{n}}\le \frac{{e}^{-x/2}}{2}$ . For which x > 0 does the generalized ratio test imply convergence of $\sum _{n=1}^{\mathrm{\infty }}{a}_{n}$? Tazmin Horton 2021-05-05

## B. G. Cosmos, a scientist, believes that the probability is $\frac{2}{5}$ that aliens from an advanced civilization on Planet X are trying to communicate with us by sending high-frequency signals to Earth. By using sophisticated equipment, Cosmos hopes to pick up these signals. The manufacturer of the equipment, Trekee, Inc., claims that if aliens are indeed sending signals, the probability that the equipment will detect them is $\frac{3}{5}$. However, if aliens are not sending signals, the probability that the equipment will seem to detect such signals is $\frac{1}{10}$. If the equipment detects signals, what is the probability that aliens are actually sending them? Ernstfalld 2021-03-07 usagirl007A 2021-03-06