# Statistics

### Featured Answers

### Organizing and Summarizing Data

- Measures of Center
- Measures of Variability
- Categorical Graphs
- Simple Quantitative Displays
- Frequency Distribution
- The Histogram
- Measuring Relative Position
- Boxplots
- Linear Transformations
- What is Statistics?
- Sampling Techniques
- Observational Studies, Experiments, and Surveys
- Experimental Design
- Basic Probability Concepts
- Combinations and Permutations
- Addition Rule
- Multiplication Rule
- Conditional Probability
- Venn Diagrams and Tree Diagrams
- Two-Way Tables
- Uniform Distribution
- The Standard Normal Distribution
- Real-Life Applications of the Normal Distribution
- Assessing Normality
- Probability Distribution
- Mean and Standard Deviation of a Probability Distribution
- Law of Large Numbers
- Addition Rules for Variances
- Properties of a Binomial Experiment
- Calculating Binomial Probabilities
- Geometric Probabilities
- Sampling Distribution and Statistics
- Sampling Distribution of a Proportion
- Central Limit Theorem
- Confidence Intervals
- Hypothesis Testing
- Statistical Significance
- Type I and Type II Errors
- One-sample z test
- Two-sample z test
- z Confidence intervals for the Mean
- One-sample t test
- Matched-pair t test
- Two-sample t test
- t Confidence intervals for the Mean
- Confidence Intervals for p
- One-sample Hypothesis Test for p
- Two-sample Hypothesis Test for p
- Chi-Square Distribution
- Goodness of Fit Test
- Chi-Square Tests for Independence and Homogeneity
- Independent and Dependent Variables
- Least Squares Regression Line (LSRL)
- Residual Plots and Outliers
- Correlation and Coefficient of Determination
- Confidence Interval for the Slope
- t Test for the Slope and the Correlation Coefficient
- Prediction Intervals
- Hypothesis Testing for the Standard Deviation
- Nonlinear Transformations of Data
- Nonparametric Statistics
- Analysis of Variance
- Question #b9a4f
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- What is the probability that a hand of 13 cards dealt from a standard deck will contain no hearts?
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- How do you write an algebraic expression for: the number of sheep should not be more than 4?
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- Men ages(20-29) have meanheight 69.3 with s.dev of 2.5 in. An analyst wonders if sd of majorleague players less than 2.5 in. Heights of 20 random players are:72, 74, 71, 72,76,70,77,75,72,72,77,73,75,70,73,74,75,73,74,73. Can you help me find the P value?
- Question #cba2e
- What are the minimum, first quartile, median, third quartile, and maximum of the following data set?: 37, 42, 44, 46, 47, 49, 51, 53, 54, 55, 57, 61, 63
- Question #8b55f
- 1545 subjects were given ginko & 1524 placebo. In ginko group, 246 developed dementian & in the placebo it was 277 with dementia. Significance level=0.01 to test claim(ginko is effective in dementia) Can you test claim and construct confidence interval?
- Why is the standard deviation an important measure of variance?
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- There are 5 Red, 5 green, and 5 blue cubes in a bag. How many color combinations can be made from a single drawing of 5 random cubes?
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- What is the formula #("group size")/("total population")times"sample size"# used for?
- 10 apples, 4 of which are rotten, are in the refrigerator. 3 apples are randomly selected without replacement. Let the random variable x represent the number chosen that are rotten. What is the mean and standard deviation of x?
- A linear regression equation for a data set has a correlation coefficient of r=0.4. Would you be conﬁdent using your equation to predict what will happen outside of the data set?
- If you roll a die #100# times and get #15# ones, what is the probability that the die is not fair? What about if you get #5# ones?
- What is a linear regression equation?
- If six pairs of data yield an r = 0.789 and a regression equation of y= 4x-2, what is the best predicted value of y when x = 5?
- What is the regression equation based on the following?: {(1,2),(2,3),(4,2),(5,6),(8,7)}
- The probability that a contractor will get a plumbing contract is 2/3 and the probability that he will get an electric contract is 5/9. If the probability of getting at least one contract is 4/5, what is the probability that he will get both?
- If a sample size is sufficiently large, should the mean and median significantly differ?
- What is the difference between modal and median value of the following set: {20.0, 20.4, 21.6, 20.8, 22.2, 19.4, 20.6, 21.3, 19.0, 20.6, 19.9, 19.3, 20.3, 20.9, 20.1, 19.5}?
- What is the standard deviation of {7, 2, 4, 6, 8, 11}?
- What is the standard deviation of {77, 26, 41, 26, 84, 21}?
- What is the standard deviation of {7, 2600, 7, 8, 7, 7}?
- What is the probability of drawing a 6 from a deck of cards?
- "There are three kinds of lies : lies, damned or white lies and statistics"- explain?
- Among the contestants in a competition are 43 women and 21 men. If 3 winners are randomly selected, what Is the probability that they are all men?
- If every person in a room shakes the right hand of every other person in the room, there are 36 possible handshakes. How many people are in the room?
- A fair die is tossed once. Let the event {A} is getting an even number, the event {B} - number 2 #>=# 3. How do you find P(A U B), P(A/B)? Are the events A, B dependent or not?
- If a fair coin is tossed 6 times, what is the probability to get exactly 2 heads? at most 2 heads?
- There are 98 ﬂowers in the bride's bouquet. If 25 of the ﬂowers are roses, approximately what percent of the flowers in the bouquet are not roses?
- What is mean and standard deviation of the following data: 2, 4, 7, 10, 12?
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- A contractor has a 0.05 probability of making 200,000, a 0.5 probability of making 14,000, a 0.02 probability of losing 1,100,000, and a 0.43 probability of breaking even. What is the contractor‘s expected value?
- The 6 entries in Claudia's checkbook ledger show both deposits and withdrawals. Claudia wrote down $100, -20, -35, $250, -$150, and -85. What is the mean dollar amount for these entries?
- A camera's flash mechanism fails on 14% of shots. If 20 shots are taken using the ﬂash, what is the probability that the ﬂash fails exactly twice?
- A random sample of size 36 is to be selected from a population that has a mean of μ = 50 and a standard deviation of 10. What is the standard score for a sample value of 40?
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- How do you express the conﬁdence interval #0.111 < p < 0.333# in the form #p +- E#?
- Past ﬂu cases in the Remulak school system #(n = 500)# were 15 per week. For the entire state, the weekly average was 16 and the standard deviation was 15.1. Are the kids in Remulak as sick as kids throughout the state?
- Two power generating units A and B operate in parallel to supply the power requirement of a small city. If there is failure in the power generation what is the probability that the city will have its supply of full power?
- If you roll a regular 6-faced die 1200 times, about how many times would you expect to get a 4?
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- Casle, Matthew, Nick, Breayn, and Monika are all running for the president, vice president, and secretary for the Spanish Club. How many possible ways can these students be chosen for the positions?
- A piggy bank contains a certain number of coins, of which 53 are dimes and 19 are nickels. The remainder of the coins in the bank are quarters. If the probability of randomly selecting a quarter is #1/4#, how many quarters does the bank contain?
- If the sample mean = 50, population mean = 44, sample standard deviation = 6, and sample size = 9, what is the one sided t-score of the sample?
- What are the variance and standard deviation of {49, 49, 52, 53, 58, 62, 68, 75}?
- If a group of data has a mean of 9 and a standard deviation of 2.5, what is the interval that should contain at least 93.8% of the data?
- A survey of 144 retail stores revealed that the average price of a microwave was $375 with a standard error of $20. What is the 80% confidence interval of the true average price of the microwave?
- Let the random variables X and Y have the joint pmf #f(x,y)=(x+y)/32#, #x=1,2#, and #y=1,2,3,4#. What are the means #mu_x# and #mu_y#, the variances #sigma ""_x^2# and #sigma "" _y^2#, and the correlation coefficient #rho#?
- Jeremy Lin can hit a free throw 81% of the time. Suppose that every free throw is an independent event. In a 10- free throw practice, what is the probability that Jeremy Lin will hit all 10 shots?
- In a bag of M&M's you have 8 reds, 10 browns, 6 yellows, and 6 greens. What is the probability of picking a red, then a brown, then a green, and then a yellow M&M?
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- Trevor bought 3 new pairs of jeans and 2 new sweaters for school. How many different clothing combinations can he make?
- 5 girls and 2 boys are arranged in a straight line for several photographs to be taken. How many different arrangement are possible if (a)there are no restrictions(b) the boys must be separated?
- If 2% of the batteries manufactured by a company are defective, what is the probability that in a case of 144 batteries, there are 3 defective ones?
- Approximately 80% of the students who take statistics pass the class. If 12 people take the class, what is the expected value and standard deviation of the number of people who pass the class?
- A standard die is rolled 4 times. What is the probability of rolling two 1s, one 2, and one 3?
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- Let Y={a,b,c,d,e,f,i,j} and a 4letter word is to be formed without replacement.How many words can be formed if the word must contain both vowels and consonants?
- A medical researcher says that less than #25%# of US. adults are smokers. In a random sample of #200# US. adults, #18.5%# say that they are smokers. At #alpha = 0.05#, is there enough evidence to reject the researchers claim?
- F two cards are drawn without replacement from an ordinary deck, what is the probability that the second card is red, given that the first card was a heart?
- What are the odds of rolling a number less than 3 when a fair die is rolled?
- An election ballot ask voters to select four city commissioners from a group of 15 candidates. In how many ways can this be done?
- If there are 5 different games to buy and you only want to buy 3, how many combinations are there?
- To win a particular lottery game a player chooses 5 numbers from 0 to 63. If all five numbers that the player selected match the winning numbers in any order, then the player wins. What is the probability that the winning numbers are 7, 0, 29, 45, and 60?