 # Get help with statistics and probability

Recent questions in Statistics and Probability IMLOG10ct 2021-11-23 Answered

### You roll a die. If it comes up a 6, you win 100. If not, you gettoroll again. If you get a 6 the second time, you win 50. If not, you lose. Find the expected amount you'll win. erurnSopSoypegx 2021-11-23 Answered

### A researcher was interested in knowing whether the mean weight of the second baby is higher, lower, or about the same as the mean weight of the first baby for women who have at least two children   Maaghu 2021-11-21 Answered

### In the article "Graphical Display of Two-Way Contingency Tables", R. Snee presented data on hair color and eye color among 592 students in an elementary statistics course at the University of Delaware. Raw data for that information are presented on the WeissStats site. Use the technology of your choice to do the following tZSKs, and interpret your results. a) Obtain both a frequency distribution and a relative-frequency distribution for the hair-color data. b) Get a pie chart of the hair-color data. c) Determine a bar chart of the hair-color data. d) Repeat parts (a)-(c) for the eye-color data. klytamnestra9a 2021-11-19 Answered

### Your math test scores are 68, 78, 90, and 91. What is the lowest score you can earn on the next test and still achieve an average of at least 85? Getting an Answer Solve your inequality to find the lowest score you can earn on the next test and still achieve an average of at least 85. What score do you need to earn? wurmiana6d 2021-11-19 Answered

### Ron Larson - Calculus 11th Edition Chp 3.3 Increasing and decreasing functions and the first derivative test. Please show work and explain steps, thank you. Modeling Data. The end-of-year assets of the Medicare Hospital Insurance Trust Fund (in billions of dollars) for the years 2006 through 2014 are shown. 2006: 305.4 2007: 326.0 2008: 321.3 2009: 304.2 2010: 271.9 2011: 244.2 2012: 220.4 2013: 205.4 2014: 197.3 (Source: U.S. Centers for Medicare and Medicaid Services) (b) Use a graphing utility to plot the data and graph the model. veudeje 2021-11-19 Answered

### The data for the joint probability mass function of X and Y (two different measurement systems) are given in the table below. a) Calculate the marginal distributions of X and Y and plot them. b) Select one of the Y values from the table and find the conditional probability mass function of X for that Y value you have selected and plot it. c) Show whether X and Y are independent or not. d) Calculate the covariance of (X,Y) i.e. Cov(X,Y). \begin{array}{|c|c|}\hline f(x,y) & 1 & 2 & 3 & 4 \\ \hline 10 & 0.05 & 0 & 0.1 & 0 \\ \hline 20 & 0.1 & 0.1 & 0.05 & 0.05 \\ \hline 30 & 0.05 & 0 & 0.15 & 0 \\ \hline 40 & 0.1 & 0.15 & 0.05 & 0.05 \\ \hline \end{array} puntgewelb5 2021-11-18 Answered

### The Great White Shark. In an article titled “Great White, Deep Trouble” (National Geographic, Vol. 197(4), pp. 2–29), Peter Benchley—the author of JAWS—discussed various aspects of the Great White Shark (Carcharodon carcharias). Data on the number of pups borne in a lifetime by each of 80 Great White Shark females are provided on the WeissStats site. Use the technology of your choice to a. obtain frequency and relative-frequency distributions, using single-value grouping. b. construct and interpret either a frequency histogram or a relativefrequency histogram. lilyta79jd 2021-11-18 Answered

### Look at the normal curve below, and find $$\displaystyle\mu,\ \mu+\sigma$$, and $$\displaystyle\sigma$$ $\begin{array}{|c|c|}\hline \mu & = & \\ \hline \mu+\sigma & = & \\ \hline \sigma & = & \\ \hline \end{array}$  pavitorj6 2021-11-18 Answered

### The data for the joint probability mass function of X and Y (two different measurement systems) are given in the table below. a) Calculate the marginal distributions of X and Y and plot them. b) Select one of the Y values from the table and find the conditional probability mass function of X for that Y value you have selected and plot it. c) Show whether X and Y are independent or not. \begin{array}{|c|c|}\hline f(x,y) & 1 & 2 & 3 & 4 \\ \hline 15 & 0.1 & 0 & 0.1 & 0.05 \\ \hline 20 & 0.05 & 0.05 & 0 & 0.1 \\ \hline 25 & 0 & 0.05 & 0.05 & 0.1 \\ \hline 30 & 0.1 & 0.05 & 0.15 & 0.05 \\ \hline \end{array} d) Calculate the covariance of (X,Y) i.e. Cov(X,Y). actever6a 2021-11-17 Answered

### Construct a scatterplot and identify the mathematical model that best fits the given data. Assume that the model is to be used only for the scope of the given data, and consider only linear, quadratic, logarithmic, exponential, and power models. The table li sts intensities of sounds as multiples of a basic reference sound. A scale similar to the decibel scale is used to measure the sound intensity. $\begin{array}{|c|c|} \hline \text{Sound Intensity} & 316 & 500 & 750 & 2000 & 5000 \\ \hline \text{Scale Value} & 25.0 & 27.0 & 28.75 & 33.0 & 37.0 \\ \hline \end{array}$ deliriwmfg 2021-11-17 Answered

### Suppose X and Y are random variables with joint density function $$\displaystyle{f{{\left({x},{y}\right)}}}={\left\lbrace{0.1}{e}^{{-{\left({0.5}{x}+{0.2}{y}\right)}}}\right.}$$ if $$\displaystyle\geq{0},\ {y}\geq{0},{0}$$ otherwise. Find the following probabilities. $$\displaystyle{P}{\left({Y}\geq{1}\right)}$$ vetrila10 2021-11-16 Answered

### Using data from the 2000 census, a random sample of 348 U.S. residents aged 18 and older was selected. The two-way table summarizes the relationship between gender and housing status for these residents. $\begin{array}{|c|c|}\hline & \text{Male} & \text{Female} & \text{Total} \\ \hline \text{Own} & 132 & 122 & 254 \\ \hline \text{Rent} & 50 & 44 & 94 \\ \hline \text{Total} & 182 & 166 & 348 \\ \hline \end{array}$ Make a graph that displays the relationship between gender and housing status for the members of the sample. Briefly describe the association. osi4a2nxk 2021-11-16 Answered

### Make a scatterplot for the data below on the number of people working on farms in various years, and draw a line of best fit. Describe the correlation as strong positive, strong negative, or little to none. $\begin{array}{|c|c|}\hline Year & 1940 & 1950 & 1960 & 1970 & 1980 & 1990 \\ \hline \text{Number of farm workers in thousands} & 8995 & 6858 & 4132 & 2881 & 2818 & 2864 \\ \hline \end{array}$ Michael Dennis 2021-11-15 Answered

### The amount of cereal that can be poured into a small bowl varies with a mean of 1.5 ounces and a standard deviation of 0.3 ounces. A large bowl holds a mean of 2.5 ounces with a standard deviation of 0.4 ounces. You open a new box of cereal and pour one large and one small bowl. a) How much more cereal do you expect to be in the large bowl? b) What 's the standard deviation of this difference? c) If the difference follows a Normal model, what's the probability the small bowl contains more cereal than the large one? d) What are the mean and standard deviation of the total amount of cereal in the two bowls? e) If the total follows a Normal model, what's the probability you poured out more than 4.5 ounces of cereal in the two bowls together? f) The amount of cereal the manufacturer puts in the boxes is a random variable with a mean of 16.3 ounces and a standard deviation of 0.2 ounces. Find the expected amount of cereal left in the box and the standard deviation. leviattan0pi 2021-11-14 Answered

### Each night different meteorologists give us the probability that it will rain the next day. To judge how well these people predict, we will score each of them as follows: If a meteorologist says that it will rain with probability p, then he or she will receive a score of $$\displaystyle{1}-{\left({1}-{p}\right)}^{{2}}$$ if it does rain $$\displaystyle{1}-{p}^{{2}}$$ if it does not rain We will then keep track of scores over a certain time span and conclude that the meteorologist with the highest average score is the best predictor of weather. Suppose now that a given meteorologist is aware of our scoring mechanism and wants to maximize his or her expected score. If this person truly believes that it will rain tomorrow with probability $$\displaystyle{p}\cdot$$, what value of p should he or she assert so as to maximize the expected score? Susan Munoz 2021-11-14 Answered

### The salaries of pediatric physicians are approximately normally distributed. If 25 percent of these physicians earn below 180, 000 and 25 percent earn above 320,000, what fraction earn (a) below 250,000; (b) between 260,00 and 300,000? Idilwsiw2 2021-11-12 Answered

### The monthly worldwide average number of airplane crashes of commercial airlines is 2.2. What is the probability that there will be (a) more than 2 such accidents in the next month? (b) more than 4 such accidents in the next 2 months? (c) more than 5 such accidents in the next 3 more than 5 such accidents in the next 3 months? Explain your reasoning! snijelihd 2021-11-11 Answered

### The annual rainfall (in inches) in a certain region is normally distributed with $$\displaystyle\mu={40}$$ and $$\displaystyle\sigma={4}$$ What is the probability that, starting with this year, it will take over 10 years before a year occurs having a rainfall of over 50 inches? What assumptions are you making? adOrmaPem6r 2021-11-10 Answered

### Suppose that X is a normal random variable with mean 5. If P{X>9}=.2, approximately what is Var(X)? crapthach24 2021-11-10 Answered

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