9. Measurements of the diameters of a random sample of 13 ball bearings made by machine X during one week showed a mean of 8.22 mm and a standard deviation of 0.38 mm. However, other measurements of the diameters ofa random sample of 11 ball bearings made by machine Y during the same week showed a mean of 7.68 mm and a standard deviation of 0.42 mm. Assuming the diameters are normally distributed with equal variance, a) Construct a 99% confidence interval for the difference in the true mean diameters of ball bearings made by the two machines. b) Based on your answer in part (a), are you 99% confident that the true mean diameters of ball bearings made by machines X and Y are not equal? Justify your answer.

Q: 3. The height of 1000 students are approximately normally distributed with a mean of 174.5 cm and a…

A: Given: Mean = 174.5 Population Standard deviation =  6.9

Q: In Country A, the population mean height for 10-year-old girls is 54.8 inches with a standard…

A: Given: Population Mean μ=54.8 Sample Size n=15 Sample Standard Deviation s=2.8 Sample Mean X¯=53.3

Q: (a) What is the probability that a randomly selected cylindrical metal bar has a length longer than…

A: here mean = 11 cm standard deviation = 0.25 cm X= length of cylindrical metal bar

Q: By definition, jumbo shrimp are those that require between 10 and 15 shrimp to make a pound. Suppose…

A:

Q: 8. A sociologist focusing on popular culture and media believes that the average number of hours per…

A: Given : Mean : d = X1 - X2    = 1 σ1 = 2.3σ2 = 2.5 σd = σ12n1+σ22n2     = 2.3250+2.5250= 0.2308=…

Q: 2. From a random sample of 10 students in a production management class, that covers a project…

A: Given,

Q: Suppose the annual consumption of chicken mean is 20.84 pounds per person, and that thestandard…

A: From the given information,Population mean = 20.84 pounds,Standard deviation = 9.193 pounds,And…

Q: 2) Collect your own random sample of 6 sodas from a normal distribution with a mean of 12 fluid…

A: From the given information, a random sample of 6 sodas from a normal distribution with a mean of 12…

Q: If x represents a random variable with mean 117 and standard deviation 40, then the standard…

A: Given : Mean , u = 117  standard deviation, σ = 40

Q: The mean annual cost of automobile insurance is $939. Assume that the standard deviation is = $245.…

A: We have given that.   X~N( μ , ?^2 )   μ=939 , ?=245   , n/50   Z-score =( x - μ )/?   NOTE:-…

Q: 9. The Taylor Steel Company wants to determine whether there is a significant difference in…

A: Solution: Given information: n1= 130 Sample size of day shiftn2= 120 Sample size of night shiftx1=…

Q: Suppose the mean number of people attending all 2017 Veterans Day celebrations held in Virginia is…

A: The question is about sampling dist. Given : Popl. mean no. of people attending all 2017 Veterans…

Q: 1. If the measure of systolic blood pressure is normally distributed with a mean of 120 and a…

A: Hello, since your question has multiple parts, we will solve the first question for you. if you want…

Q: If a random sample of size 14 is drawn from a normally distributed population with mean 43.5…

A: Let, X=the variable Given that X follows a normal distribution with mean=43.5 and standard…

Q: If x represents a random variable with mean 125 and standard deviation 36, then the standard…

A: For a random sample of 81, X –bar follows normal with mean value of 125 and standard deviation of 4.…

Q: A researcher wishes to determine whether the salaries of professional nurses’ employees by private…

A: Let 1 represents Private and 2 represents the Government. State the Given values, State the Null…

Q: Assume that for the population of MBA (Supply Chain Management), the average starting salary is PKR…

A: From the provided information, Mean (µ) = PKR 72,000/- Standard deviation (σ) = PKR 20,000/-

Q: In a normal distribution with mean 375 and standard deviation 48, how large a sample must be taken…

A: It is an important part of statistics. It is widely used.

Q: Suppose that the distribution of typing speed in words per minute (wpm) for experienced typists…

A:

Q: If x represents a random variable with mean 137 and standard deviation 35, then the standard…

A: Central Limit Theorem for mean: If a random sample of size n is taken from a population having mean…

Q: ording to one pollster, 47% of children are afraid of the dark. Suppose that a sample of size 20 is…

A: Consider "p" be the true proportion which represents the proportion of children that are afraid of…

Q: 1. The lifetimes of a certain brand of LED light bulbs are normally distributed with a mean of…

A: Let X represents the lifetime of a certain brand of a LED light bulbs. Therefore X ~ normal…

Q: 36% of a population has a particular characteristic. If samples of size n=400 are taken, calculate…

A: Solution: From the given information, the probability of a particular characteristic is 0.36 and the…

Q: Suppose that an airline uses a seat width of 17.1in. Assume men have hip breadths that are normally…

A: The Z-score of a random variable X is defined as follows: Z = (X – µ)/σ. Here, µ and σ are the mean…

Q: 1.A study of the amounts of time (in hours) college freshmen study each week found that the mean is…

A:

Q: 1. If the standard deviation of the mean for the sampling distribution of random samples of size 36…

A:

Q: n a small factory producing bamboo products, the standard acceptable measurement for a bamboo…

A: Lengths are between  10.85 cmand 12.075 cm SD = Standard Deviation   6% of the straws are rejected…

Q: Suppose that the sampling distribution of size 10 has a mean of 30 and standard deviation of 3.…

A:

Q: An airliner carries 400 passengers and has doors with a height of 75 in. Heights of men are normally…

A: Given,mean(μ)=69standard deviation(σ)=2.8

Q: 6. On a test of motor coordination, the population of average bowlers has a mean score of 24, with a…

A: given that  μ=24σ=6x1 =26 for n1=30x2 =18 for n2=30

Q: Suppose that the height of women in Dakar, Senegal is normally distributed with mean 58 inches and…

A: Note- As per our policy we can answer only the first 3 sub-parts of a question. If you want…

Q: 2) A researcher reports that the average salary of assistant professors in a certain state is…

A: n=30x=43260s=5230claim:μ=42000H0:μ=42000H1:μ±42000

Q: 1. Suppose the mean life span of a randomly selected Chihuahua dog is normally distributed with a…

A: Solution

Q: If x represents a random variable with mean 131 and standard deviation 40, then the standard…

A: Given that ; u = 131  ? = 40 Sample size ( n) = 100 Here we use the concept of standard normal…

Q: A small computing center has found that the number of jobs submitted per day to its computers has a…

A: Let X be a random variable such that X: Number of jobs submitted per day to its computers We know,…

Q: Suppose the mean number of people attending all 2017 Veterans Day celebrations held in Virginia is…

A: Given that: Mean number of people attending all 2017 veterans day celebrations held in Virginia,…

Q: Suppose that the starting salaries of MBAS at Wilfrid Laurier University (WLU) are normally…

A:

Q: A marine biologist claims that the mean lengin of mature female pink seaperch is difere sample of 8…

A: Option (B) is the right claim Let X1 represents the sample collected in Fall X2 represents the…

Q: Suppose weights of running shoes have an unknown distribution with mean 11 and standard deviation 2…

A: The standard deviation from the sample mean distribution is obtained below: From the information,…

Q: Assume the number of physical damage losses for houses as a result of hurricane Irma in Barbuda is…

A:

Q: If the average length of all low-weight babies at the time of birth is known to be 36.5 centimeters…

A: Given Data: Mean=36.5 SD=2.4

Q: 4. A public utility company assumes that annual water consumption (measured in cubic meters) of…

A: Given,mean(μ)=120standard deviation(σ)=55

Q: Suppose the current measurements made on a conductor wire track follow a normal distribution with…

A: Given, Suppose the current measurements made on a conductor wire track follow a normal distribution…

Q: Suppose that the starting salaries of MBAs at Wilfrid Laurier University (WLU) are normally…

A: Given the data MBA's at WPUNJ MBA's at Rutgers Mean μ1=62000 Mean μ2=60000 SD, σ1= 14500 SD,…

Q: If x represents a random variable with mean 137 and standard deviation 16, then the standard…

A: Let X be the random variable. It is given that X is normally distributed with mean 137 and standard…

Q: In a poll conducted by the General Social Survey, 81% of respondents said that their jobs were…

A:

Q: 4. The specification of the melting point of an alloy is 1200 degrees Celsius. If the melting point…

A: Claim : the composition of the alloy will have to be changed.

Q: 4. According to a 2019 Federal Reserve report, 54% of U.S. young adults who went to college took on…

A: Given that, (a) The Mean and Standard deviation of the sampling distribution of sampling proportion…

Q: 1. The breaking strength of a rivet has a mean value of 10,000 psi and a standard deviation of 500…

A: Given: μ=10,000σ=500 a. The probability that the sample mean breaking strength for a random sample…

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.