A tool company claims that the mean number of defective screws they produce per box is 72. The mean number of defective screws in 100 randomly chosen boxes was found to be 76, with a standard deviation of 19. Test this hypothesis.

Q: a manufacturer claims that the mean lifetime of its fluorescent bulbs is 1050 hours. a homeowner…

A: Given n=40 Standard deviation =80 Xbar=1030 Level of significance=0.05 Mu0=1050

Q: If a sample has a mean of 250 and a standard deviation of 15, what is the value in the data set that…

A:

Q: If a sample has a mean of 100 and a standard deviation of 6, what is the value in the data set that…

A:

Q: If a sample has a mean of 150 and a standard deviation of 9, what is the value in the data set that…

A: Given,mean(μ)=150standard deviation(σ)=9Z-score=1.58

Q: A car insurance company tells its prospective customers that they can save an average of at least…

A:

Q: The sale price of a certain model of grand piano across the country is approximately normally…

A: Given: Mean = 70000, Standard deviation =5400 Let Y defines the sale of certain model of grand…

Q: A company make LED light bulbs and claims that they have a life of 20,000 hours. A sample of 16bulbs…

A: From the given information, Sample size (n) = 16 Sample mean (x-bar) =19706 Standard deviation (s) =…

Q: A firm specializing in the preparation of income tax returns, claims the mean refund for customers…

A: Given  μ=150, n=12, x̄=125, s=43

Q: Suppose the scores of students on an exam are normally distributed with a mean of 276 and a standard…

A: X~N(μ= 276 , σ= 59 ) μ= 276 , σ= 59 Formula for Z-score Z=(X-μ)/σ

Q: Suppose the scores of students on an exam are normally distributed with a mean of 458 and a standard…

A: A Z-score is a numerical measurement that describes a value's relationship to the mean of a group of…

Q: In a certain city, the average 20- to 29-year old man is 69.8 inches tall, with a standard deviation…

A:

Q: A marine researcher claims that the stomachs of blue crabs from one location contain more fish than…

A: From the provided information,

Q: A tire manufacturer claims (based on years of experience with tires) that the mean mileage is…

A: Given: n= 101.0 ,x̄= 31000.0 ,s= 5000.0 µ= 35000.0 ,significance level(∝)= 0.02Now here using…

Q: A researcher claims that the standard deviation of the number of deaths annually from typhoons in…

A:

Q: A study determined the average amount a person spends on candy during Halloween is $80 with a…

A: Here, μ=80 and σ=15

Q: The City Transport and Traffic Management Office (CTTMO) study of 8000 vehicles that passed the…

A: Given,The CTTMO study of 8000 vehicles that passed the diversion highway foundMean (μ) = 61 mphand…

Q: The salaries of 300 employees of a certain factory in Baguio City have a mean of P6,500 and a…

A:

Q: A job placement director claims that the average starting salary for nurse is $26000. A sample of 18…

A: Given,sample size(n)=18sample mean(x¯)=25620standard deviation(s)=680α=0.05

Q: If a sample has a mean of 48 and a standard deviation of 3.2, what is the value in the set that…

A:

Q: In a certain city, the average 20- to 29-year old man is 72.5 inches tall, with a standard deviation…

A: From the provided information, The height of men is normally distributed with mean (µ) = 72.5 inches…

Q: The heights of women are normally distributed with a mean of 63.6 inches and a standard deviation of…

A: Given that μ=63.6 and σ=2.5. a) The requirement that women must be at least 70 inches tall to join.…

Q: A candy store sells about 8 million pieces of candy per day with a standard deviation of 300,000…

A: Given : Let X : Number candy that they sell in a given day           μ = 8 million i.e   Mean (μ) =…

Q: In order to increase customer service, a muffler repair shop claims its mechanics can replace a…

A: Given: x¯=11.6s=2.1n=6 Hypothesis: Null hypothesis: H0: μ=12Alternate hypothesis: H1: μ<12 The…

Q: The current government economic survey wishes to know, with 96% confidence, the average household…

A:

Q: A tool company claims that the mean number of defective screws they produce per box is 72. The mean…

A:

Q: A trucking company determined that the distance traveled per truck per year is normally​…

A: Given information- Mean weight of the bears, µ = 80 thousand miles Population standard deviation, σ…

Q: A company pays their employees an average of $52,500 per year. If the standard deviation for the…

A: Given : A company pays their employees an average of $52,500 per year. If the standard deviation for…

Q: If the average salary of a computer programmer is $71, 800 with a standard deviation of 13, 000,…

A: I am attaching image so that you understand each and every step.

Q: A grocery store's sales experience indicates that its daily apple sales follow a normal distri-…

A: (b) Obtain the cut off point for the top 10% of all daily apple sales. The cut off point for the top…

Q: A trucking company determined that the distance traveled per truck per year is normally​…

A: Solution-: Let, X= The distance traveled per truck per year Given: We find, P[ either less than…

Q: An LED lightbulb manufacturer produces lights with a mean lifespan of 10,000 hours and a standard…

A: the PDF of normal distribution is = 1/σ * √2π * e ^ -(x-u)^2/ 2σ^2standard normal distribution is a…

Q: The Virginia Cooperative Extension reports that the mean weight of yearling Angus steers is 1152…

A:

Q: What is the z-score of a value of 27, given a set mean of 24, and a standard deviation of 2?

A:

Q: A trucking company determined that the distance traveled per truck per year is normally distributed,…

A: A normal distribution is a continuous type probability distribution.It is also known as a…

Q: Statewide, the population as a whole watches 6.2 hours of TV per day. A random sample of 1017 senior…

A: Given data is appropriate for testing of hypothesis to test z-test for single mean because it is a…

Q: For a recent 10k​ run, the finishers are normally distributed with mean of 56 minutes and a standard…

A: Given data,μ=56σ=13P(45<X<70)=?

Q: reasonably regarded as a a sample from a standard deviation

A: Given: In a sample of 400 male students, it was observed that they have a mean height (of 55+18)…

Q: In a certain city, the average 20- to 29-year old man is 72.5 inches tall, with a standard deviation…

A:

Q: A report from the Illinois Department of Wildlife indicates that when a car and deer collide, there…

A: Given: 40 deer fatalities per 100 collisions between a car and a deer

Q: The daily sales at a convenience store have a mean of $1280 and a standard deviation of

A: As given, the daily sales at a convenience store have a mean of $1280 and a standard deviation of…

Q: A local Chamber of commerce Claims that the mean family income in aſcity is $12,250 An economist…

A: The one-sample z-test is used to test whether the mean of a population is greater than, less than,…

Q: A researcher reports that the average income of system analysts in Makati is P44,000 per month. A…

A: Given: Average(μ)=44000sample size(n)=30Sample mean(x¯)=45800Standard deviaion(s)=5400

Q: A job placement director claims that the average starting salary for nurse is $26000. A sample of 18…

A: Yes, There is enough evidence to reject the directors claim at 5% l.o.s.

Q: If the standard deviation had been larger, the power would have been larger.

A: Here given data of two sample t test   Power of test = 0.752923

Q: In a certain​ city, the average​ 20- to​ 29-year old man is 72.5 inches​ tall, with a standard…

A:

Q: Toby's Trucking Company determined that on an annual basis, the distance traveled per truck is…

A: It is given that the mean and standard deviation are 50,000 and 12,000.

Q: A realtor claims that in a certain neighborhood, the average house is worth $200,000. Having been…

A:

Q: If a raw score is 28 in a distribution in which the mean is 20 and the standard deviation is 2, what…

A: Given information- Population mean, µ = 20 Population standard deviation, σ = 2 We have to find the…

Q: A cigarette manufacturer claims that its brand of cigarette contains on the average 5mg of tar and…

A: Given : n=25 , X-bar=6  , s=2 , μ0=5  Assume that , α=0.05 Here , we want to test the cigarette…

Q: Cushman and Wakefield reported that the average annual rent for office space in Tampa was $17.63 per…

A: H0 : ? =17.63     H1 : ? ≠17.63     Population mean = ? = 17.63 Sample S.D = s =3.64…

Types of Bias

Statistics is the study of data collection, organization, analysis, interpretation, and presentation. Statistical bias is a characteristic of a statistical technique or its findings in which the expected value deviates from the actual root quantitative parameter being estimated. According to the actual definition of bias, it refers to the tendency of a statistic to overestimate or underestimate a parameter.