# Statistics

**Statistics**

A company makes batteries with an average life span of 300 hours with a standard deviation of 75 hours. Assuming the distribution is approximated by a normal curve fine the probability that the battery will last . Less than 250 hours b. Between 225 and 375 hours c. More than ...

**statistics**

Recent studies, as summarized, for example, in E. Mortensen et al. (2002). The association between duration of breastfeeding and adult intelligence. Journal of the American Medical Ass o ciation , 287 , 2365–2371, suggest that breast-feeding of infants may increase their ...

**statistics**

A manufacturer ships toasters in cartons of 20. In each carton, they estimate a 10% chance that any one of the toasters will need to be sent back for minor repairs. What is the probability that in a carton, there will be exactly 2 toasters that need repair?

**English**

Can you proof read or correct my sentence? Why does immigrant migrate even though we have a law as being illegal? There are various reasons for illegal immigrant migrating such as seeking for job, for safe life and for quality of life. Because of the unemployment, people tends...

**Statistics**

Answer the following questions. (a) The random variable x is distributed normally, with x~N(80,100) Find the probability that x is greater than 90. x >90. (b) Find P(x<85). (c) Find P(76<x<84).

**Statistics**

There is a 0.0416 probability that a best-of-seven contest will last four games, a 0.0804 probability that it will last five games, a 0.2132 probability that it will last six games, and a 0.6648 probability that it will last seven games. Find the mean and standard ...

**Statistics**

The probability of a randomly drawn individual having blue eyes is 0.51. A) What is the probability that seven people drawn at random all have blue eyes? (b) What is the probability that one of the sample of seven has blue eyes?

**Statistics**

If the slope of the regression line is negative and the correlation coefficient is -0.5, coefficient of determination is: r = -0.5 r2 = 0.25 but because slope of regression line is negative, then coefficient of determination would be also negative. r2 = -0.25

**Statistics**

The correlation coefficient between X and Y is the same as the correlation coefficient between Y and X: True or False - I believe it is True because calculating the correlation coefficient for X and Y and Y and X will give you the same answer.

**Statistics**

If the slope of the regression line is negative and the correlation coefficient is -.5, coefficient of determination is: - It would be -0.25. Correlation coefficient = r and coefficient of determination = r^2. Then, coefficient of determination would be (-0.50)^2 = 0.25, but ...

**Statistics**

The correlation coefficient between X and Y is the same as the correlation coefficient between Y and X. True - If you were to find the correlation coefficient with a given data set for x and y, it would have the same correlation coefficient value as y and x. Can you check if ...

**Statistics**

In 2015, the average price of new homes in a certain suburb was $145,000. Assume that this mean is based on a random sample of 1000 new home sales and that the sample standard deviation is $24,000. Construct a 99% confidence interval for the 2002 mean price of all such homes.

**statistics**

The distance travelled in a week by sales staff employed by a nationwide security firm is approximately normally distributed with a mean of 200 miles and standard deviation of 48 miles. a) less than 80 miles, b) more than 250 miles, c) between 100 and 300 miles. d) A reduced ...

**statistics**

The professor teaching a large introductory class gives a final exam that has alternate forms, A, B, and C. A student taking the exam using Form B is upset because she claims that Form B is much harder than Forms A and C. Discuss how percentile point data might be useful to ...

**Statistics/Math**

I have population data for the last 50 years (total population for a country), that I need to make linear. In its original it has a positive relationship (looking at a scatter plot) but it is not linear. There are three smaller periods with large increases in population, which...

**statistics**

A bag contains 8 white and 3 black counters. Two counters are drawn, one after the other. Find the probability of drawing one white and one black counter, in any order. i) If the first counter is replaced ii) if the first counter is not replaced.

**Statistics**

What is the probability that the average lifetime of 25 bulbs would be no more than 1550 given mean of 1500 and standard deviation of 200 hours. I know that it is asking P(x less than or equal to 1550), x is 25, u equal 1500 and sd is 200. I'm having problems getting to the ...

**Statistics**

Please help me understand this is asking and how to solve. P(-2>Z and Z<-1)= and X~N(3,4). Find value c such that P(c<x)=.7 Thank You!

**Statistics**

IF SAT scores have approximately a normal distribution with the mean being 550 and standard deviation of 90. How can I calculate the SAT scores of the 95th percentile? Thank you

**Statistics**

Suppose that 4 cards are drawn from a well-shuffled deck of 52 cards. What is the probability that all 4 are hearts? Would the answer be 1/4, if I reduce it? Thanks

**Statistics**

Suppose x is a uniform random variable with values ranging from 40 to 60. Find the probability that a randomly selected observation exceeds 54.

**Statistics**

Suppose you are told that a 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $2.85 to $3.84. Use the fact that the confidence interval for the mean is in the form x − E to x + E to compute the sample mean and the maximal ...

**Statistics**

Suppose x is a uniform random variable with values ranging from 20 to 70. Find the probability that a randomly selected observation is between 23 and 65.

**Statistics**

Suppose x is a uniform random variable with values ranging from 40 to 60. Find the probability that a randomly selected observation exceeds 54. *** Im not sure how to do this. I thought I needed a standard deviation.

**Statistics**

In a certain population the heights of men are normally distributed with mean 168.75 and variance 42.25 those of women are normally distributed with mean 162.50 and variance 36 the probability that the mean height of a random sample of 25 men is less than 170 is

**Social Studies 1**

Geographers want to know how people living in hazard-phone areas are affected by natural disasters such as floods, hurricanes, tornadoes, and earthquakes. Although the number of natural disasters has remained relatively constant over the years- thirty per year throughout the ...

**Statistics**

A study is conducted regarding shatterproof glass used in automobiles. Twenty-six glass panes are coated with an anti-shattering film. Then a 5-pound metal ball is fired at 70mph at each pane. Five of the panes shatter. We wish to determine whether, in the population of all ...

**Basic Numeracy and statistics (math)**

A rocket is shot into the air with an initial velocity of 800m/sec. The equation h = -16t2+144t models the height of the ball. how long does it take for the rocket to hit the ground (h=0)?

**Statistics**

The director of the library believes that 25% of the library's collection is checked out. If the director is right, what is the probability that the proportion of books checked out in a sample of 545 books would differ from the population proportion by less than 5%? Round your...

**Statistics**

Could anyone help me out with the following problem? Identify the consequences (i.e. increase, decrease, or none) that the following procedures are likely to have on both bias and sampling error in an experimental study. A) Assigning treatments to subjects alphabetically, not ...

**statistics**

A new process is started and the sum of the sample standard deviation for 20 subgroups, of size 8, is 750; Compute, to 3 decimal places, the process standard deviation, σ0:

**Math (Statistics: Test Statistic, Proportion)**

The Pew Research Center Internet Project, conducted on the 25th anniversary of the Internet, involved a survey of 857 Internet users (Pew Research Center website, April 1, 2014). It provided a variety of statistics on Internet users. For instance, in 2014, 87% of American ...

**statistics**

The lifetime of a type of electric bulb has expected value µ = 475 hours and standard deviation σ = 60 hours. (a) Use the central limit theorem to determine the expected value and standard deviation of the sample mean of n such lightbulbs where n = 100, 200, or 400. (b) You ...

**Math (Statistics)**

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .30. a...

**Statistics**

A certain university has 7 vehicles available for use by faculty and staff. Five of these are vans and 2 are cars. On a particular day, only two requests for vehicles have been made. Suppose that the two vehicles to be assigned are chosen in a completely random fashion from ...

**statistics**

The Information Systems Audit and Control Association surveyed office workers to learn about the anticipated usage of office computers for personal holiday shopping. Assume that the number of hours a worker spends doing holiday shopping on an office computer follows an ...

**Business statistics**

If the arithmetic mean of two numbers is 15 and their geometric mean is 9 find the two numbers

**statistics**

I need help figuring out how to draw a tree diagram to find possible outcomes.

**statistics**

a new car buyer had the choice of 3 body styles, 2 engines, and 7 colors. How many different ways are there to select a car?

**statistics**

there are 8 women and 6 men in a department. How many ways can a committee of 4 people be selected if there must be at least two women on the committee?

**statistics**

how many ways can a person select 5 glazed doughnuts, 4 cake doughnuts, and 3 filled doughnuts from a selection of 13 glazed doughnuts, 10 cake doughnuts, and filled doughnuts?

**statistics**

in a club there are 6 men and 9 women. a committee of 1 man and 2 women is to be formed. how many different possibilities would there be in choosing the committee?

**statistics**

Mary can choose 2 books out of a selection of 9 books to read for her English class. How many different possibilities would there be in choosing the committee?

**statistics**

a florist can select five different flowers from a selection of twelve different types. How many ways can she select these flowers?

**maths, statistics**

Marks in an examination are distributed normally with a mean of 55 and standard deviation of 15. 200 students sit the exam. (a) If the passing mark is 40, what is the number of students expected to fail? (b) If you score 75 marks on the exam what do you expect your ranking to ...

**maths, statistics**

The yearly mileage accumulated by an automobile in a large car rental company’s ﬂeet is normal with mean 18000 kilometres and standard deviation 1700 miles. At the end of the year the company sells 80% of its cars, keeping the 20% with the lowest mileage. Do you think a ...

**statistics**

Find the number of ways in which 3 of 10 real estate salesperson can be ranked first, second and third according to market knowledgebility.

**probability and statistics**

For the model X=Θ+W, and under the usual independence and normality assumptions for Θ and W, the mean squared error of the LMS estimator is 1(1/σ02)+(1/σ12), where σ02 and σ12 are the variances of Θ and W, respectively. Suppose now that we change the observation model ...

**probability and statistics**

Let Θ1, Θ2, W1, and W2 be independent standard normal random variables. We obtain two observations, X1=Θ1+W1,X2=Θ1+Θ2+W2. Find the MAP estimate θ^=(θ^1,θ^2) of (Θ1,Θ2) if we observe that X1=1, X2=3. (You will have to solve a system of two linear equations.)

**statistics**

suppose a car is driven from town A to town B from town B to town C and from town C to town D which have equal distances at average speeds 20km/hr,60km/hr and 120km/hr respectively,what is the average speed for the whole journey

**statistics**

explain clearly the three meaning of "statistics" contained in the statement below "you compute statistics from statistics by statistics"

**statistics**

the percentage increase in price of four items from what they did a year earlier is 72,108,36 and 96 what is the average percentage increase in price of the four items

**Statistics**

The weight of a randomly selected shipping container follows an unknown distribution with mean 12 tons and standard deviation 2 tons. Your cargo ship always carries a load of 100 randomly selected shipping containers. a. What is the probability the load weighs more than 1,231 ...

**Statistics**

Consider the population (1,3). Suppose you take all possible samples of size n=3 with replacement. What is the sampling distribution of the sample total?

**Statistics and Probability**

A machine is designed to fill jars with 16 ounces of coffee. A consumer suspects that the machine is not filling the jars completely. A sample of 8 jars has a mean of 15.6 ounces and a standard deviation of 0.3 ounces. Is there enough evidence to support the consumer's claim ...

**Math Statistics**

They used an exponential regression model where the predictor is time in months and the response var is money measure in thousands of dollars. Alpha 4.2 and Beta is 1.03 Based on this model, how much money (in thousands) will he have after six months? I am confused by this and...

**Math Statistics**

I am confused I want to find the values of the equation of Yi=a + bxi. Time spent on twitter is the predictor variable and time spent working on twitter is the response The correlation between minutes spent on twitter and minutes spent working is -0.5 The standard deviation in...

**Probabilities and Statistics**

How does the number of study hours change during a semester? How do you determine what graph to use? I am so confused

**Statistics**

The admissions counselors at rainy University believe that the freshman class they have just recruited is the brightest yet. If they want to test this belief (that the freshmen are brighter than the other classes), what are the null and alternative hypotheses? Is this a one- ...

**Statistics**

Consider the population (1,3). Suppose you take all possible samples of size n=3 with replacement. What is the sampling distribution of the sample total?

**Statistics**

The weight of a randomly selected shipping container follows an unknown distribution with mean 12 tons and standard deviation 2 tons. Your cargo ship always carries a load of 100 randomly selected shipping containers. a. What is the probability the load weighs more than 1,231 ...

**Statistics**

LED light bulbs are manufactured with an average life span of 16 years and the bulb lifespans are known to follow an exponential distribution. a. What is the probability that a bulb will last longer than 14 years? b. What is the 50th percentile (or median) of bulb lifespans?

**Statistics**

You look at the relationship between how much time people spend on the website ‘Bookface’ and how productive they are at work. time spent on Bookface is the predictor variable, and time spent working is the response variable. correlation between minutes spent on Bookface ...

**Statistics**

A person has money worries and decides to invest in the computer industry. They want to know how the value will change over time. They used an exponetial regression model where the predictor is time in months and the response var is money measure in thousands of dollars. Alpha...

**statistics**

41% of the student body at Urban High are "cool". Mr. Uppity has devised a test for determining if a student is "cool" or not. What is the average number of students Mr. Uppity needs to test in order to find one who is "cool"? a. 3 b. 3.57 c. 2.43 d. 1.44 e. 2

**Statistics**

Billy Isastar, a famous basketball player, is not a very good free throw shooter. He manages to connect on 65% of his attempts. What is the probability that the first free throw Johnny hits in a game is on his fourth attempt? a. .015 b. .028 c. .179 d. .096

**statistics**

a survey from teeneage research unlimited found that 30% of teenage consumers receive their spending money from parttime jobs. If 5 teenagers are selected at random, find the probability that at least 3 of them have part time jobs

**Ruwaydah**

This is my hw, however i do not know to put these quotations in my sentences can someone help me? and please do not copy this!I repeat I have recently read Liane Beam Wansbrough’s article on the topic of cosmetic plastic surgery, and I am writing to express my viewpoint and ...

**Statistics**

The amount of time the university professors devote to their jobs per week is normally dis- tributed with a mean of 52 hours and a standard deviation of 8 hours. (a) What is the probability that a professor works for more than 56 hours per week? (b) Find the probability that ...

**Statistics**

The weight of bags of pretzels are normally distributed with a mean of 150 grams and a standard deviation of 5 grams. Bags in the upper 4.5% are too heavy and must be repackaged. Also, the bags in the lower 5% do not meet the minimum weight requirement and must be repackaged. ...

**statistics**

A school club consists of 22 male students and 15 female students. If 3 students are selected to represent the club in the student government, what is the probability 2 will be male and 1 will be female?

**statistics**

A music industry researcher wants to estimate, with a 90% confidence level, the proportion of young urban people (ages 21 to 35 years) who go to at least 3 concerts a year. Previous studies show that 21% of those people (21 to 35 year olds) interviewed go to at least 3 ...

**STATISTICS**

Consider a t distribution with 30 degrees of freedom. Compute P(t "greater than or equal to" -1.50). Round your answer to at least three decimal places. Consider a t distribution with 6 degrees of freedom. Find the value of c such that P(-c <t<c)=0.95. Round your answer ...

**statistics**

Find the third quartile Q3 of the list of 24 sorted values shown below. 30 32 33 34 37 37 40 42 43 48 49 50 50 52 57 59 60 61 63 65 67 71 72 7430 32 33 34 37 37 40 42 43 48 49 50 50 52 57 59 60 61 63 65 67 71 72 74

**Statistics**

Consider a t distribution with 30 degrees of freedom. Compute P(t "greater than or equal to" -1.50). Round your answer to at least three decimal places. Consider a t distribution with 6 degrees of freedom. Find the value of c such that P(-c <t<c)=0.95. Round your answer ...

**Statistics**

I am confused by the following and need some help You want to find the values for the equation ŷi=a+bxi. What is the value of the slope? time spent on Bookface predictor variable, time spent working is the response variable. correlation between minutes spent on Bookface and ...

**Statistics**

A pilot sample of 50 measurements of the breaking strength of cotton threads gave S_(pr) = 18 grams. Determine the sample size needed to obtain a 90% Confidence Interval of length 4. I tried using the sample size formula but that did not gave me the right answer, according to ...

**Statistics**

Based on data collected by the National Center for Health Statistics and made available to the public in the Sample Adult database (A-5), an estimate of the percentage of adults who have at some point in their life been told they have hypertension is 23.53 percent. If we ...

**Statistics**

Q1:(a) Make a relative frequency table of the data. Enter your answers to three decimal places. Cell Phone Owned Relative Frequency Android smartphone iPhone smartphone Blackberry smartphone Cell phone not smartphone No cell phone Total (b) Round your answers to the following ...

**College statistics- SCWK450**

One hundred students took a statistics exam where the mean score was 78. The distribution was normal. The standard deviation was 4. If Chris earned an 80 on the exam, at approximately what percentile did his grade fall? (Round your answer to the nearest whole number.)

**Statistics**

One hundred students took a statistics exam where the mean score was 78. The distribution was normal. The standard deviation was 4. If Chris earned an 80 on the exam, at approximately what percentile did his grade fall? (Round your answer to the nearest whole number.) Mean=78 ...

**Statistics**

Childhood participation in sports, cultural groups, and youth groups appears to be related to improved self-esteem for adolescents (McGee, Williams, Howden-Chapman, Martin, & Kawachi, 2006). In a representative study, a sample of n 5 100 adolescents with a history of group ...

**statistics**

A bag contains red and blue marbles. Two marbles are drawn without replacement. The probability of selecting a red marble and then a blue marble is 0 .28. The probability of selecting a red marble on the first draw is 0.5. What is the probability of selecting a blue marble on ...

**statistics**

A bag contains 7 red marbles, 2 blue marbles, and 1 green marble. If a marble is selected at random, what is the probability of choosing a marble that is not blue?

**Statistics**

Suppose that on average 10% of the people with an airline-ticket doesn't show up at the flight.For a certain flight, the plane has 100 seats and 110 tickets are sold. What is the probability that everyone who shows up will have a seat?

**Statistics**

if P(A) =1/2 and P(B)= 2/3, can the events A and B be mutually exclusive, why or why not?

**Statistics**

Based on sq foot and home prices :Create an inferential statistics (hypothesis) test using the research question and two variables your learning team developed for the Week 2 Business Research Project Part 1 assignment. Include: The research question Mock data for the ...

**Stastics**

USA snapshot presented a bar graph depicting business travelers’ impression of wait times in airport security lines over the past 12 months. Statistics were derived from Travel Industry Association of American Business Traveler Survey of 2034 respondents. Could this be a ...

**STATISTICS**

An urn contains 14 white balls and 6 red balls. two balls are to be selected in succession, at random and without replacement what is the probability that i) both balls are white, ii) the first ball in white and the second ball is red, iii) one white ball and one red ball are ...

**STATISTICS**

it is given that 3% of electric blubs manufactured by a company are defective using poisson approximation find that a sample of 100 bulbs will contain no defective exactly one defective bulb

**Statistics Maths**

Iam confused by this and need some help not sure if I am right about this = 3000-7.3x x 50 = 2635 regression equation: number of tickets = 3000 - 7.3x, where x = ticket price. If Yoncebé prices the tickets at $50, how many tickets is she predicted to sell?

**Statistics**

A basket ball player makes 70% of her free throws. She takes 7 free throws in a game, and makes 5 of her 7 throws. If the shots are independent of each other, Then what is the probability that she makes the first five and misses the last 2?

**Statistics**

A manufacturer estimates that when x units of a particular commodity are produced each month, the total cost (in dollars) will be C(x) = 1/8x^2+4x+200 and all units can be sold at a price of p(x) = 49 - x dollars per unit. Determine the price that corresponds to the maximum ...

**Statistics**

The table to the right lists probabilities for the corresponding numbers of girls in three births. What is the random variable, what are its possible values, and are its values numerical? Number of girls x P(x) 0 0.125 1 0.375 2 0.375 3 0.125

**Statistics**

by what factor should the sample size in a poll be increased in order to cut the margin of error in half

**Statistics**

by what factor should the sample size in a poll be increased in order to cut the margin of error in half

**stats**

a statistics professor rolls two balanced dice. Both fall to the floor and roll under his desk. A student in the first row informs the professor that he can see both dice. He reports that at least one of them shows a “five”. What is the probability that the other die is ...

**statistics**

professor rolls two balanced dice. Both fall to the floor and roll under his desk. A student in the first row informs the professor that he can see both dice. He reports that at least one of them shows a “five”. What is the probability that the other die is also “five”?

**statistics**

If it is discovered that 65 out of 12,800 records are misfiled, what is the filing accuracy rate?

**Statistics**

A coin is tossed 7 times. What is the probability that the number of heads obtained will be between 2 and 4 inclusive? Express your answer as a fraction or a decimal number rounded to four decimal places.