QUESTION 2 a) Measurements of the length of a random sample of 200 rods made by a certain machine during one week showed a mean of 0.824m and a standard deviation of 0.042m. Find a 95% confidence interval for the mean length of all the rods. b) Suppose that the diameters of 100 balls in a sports hall represent a random sample of the diameters of all 1546 in the sports hall. Using the table given, determine unbiased and efficient estimates of: i. the true mean. ii. the true variance. Diameters of 100 Balls in the Sports Hall Diameter Number of (inches) Balls 60-62 5 63-65 18

Q: Question 7 x~N(9,64) Calculate the 95% confidence interval for this distribution.

A: Give Xbar~N(9,64) 95% confidence interval

Q: Question 7 A researcher wishes to estimate the average height of trees in a geographic region. If…

A:

Q: In a sample of 100 patients that did not receive the flu shot, the average recovery time after being…

A: The random variable recovery time follows normal distribution. The sample size is 100. The sample…

Q: Question 7: Assuming all other factors are unchanged, a decrease of sample size will have what…

A: Assuming all other factors are unchanged, a decrease of sample size will have what result in the…

Q: The table below contains data about the English reading comprehension scores (on a scale of 1-100)…

A: Sample size n = 5 is very small Since the sample observations are collected from the same learners…

Q: Question 1 Do students in fraternities and sororities do better or worse than other students…

A:

Q: Question 2 Grace Floral Shop claims that their average daily earnings is $497. An auditor wants to…

A: Null Hypothesis (H0): μ=497, the mean earning is $497Alternative Hypothesis (H1): μ<497, i.e the…

Q: use the confidence interval to give a conclusion of the test (if possible) and also state the…

A: The 90% confidence interval for difference in proportion p1 - p2 is given by (0.04, 0.19)

Q: QUESTION 7 A production filling operation has a historical standard deviation of 6 ounces. When in…

A: We have to find given statement is true or false.

Q: The quality-control manager at a light bulb factory needs to determine whether the mean life of a…

A: Hi! Thank you for the question, As per the honor code, we are allowed to answer three sub-parts at a…

Q: QUESTION 3 A machine that produces a major part for an airplane engine is monitored closely. In the…

A: Given,margin of error(E)=0.04standard deviation(σ)=0.30α=1-0.95=0.05α2=0.025Z0.025=1.96      (from…

Q: QUESTION 1 To estimate the average time it takes to assemble a certain computer component, the…

A:

Q: Question 2. A consumer wishes to estimate the proportion of processed food items that contain…

A:

Q: Question 7) It was observed that 240 of the 400 voters randomly selected from a region supported the…

A:

Q: QUESTION 39 Suppose we calculated the 95% confidence interval for the mean amount of oil recovered…

A: From the given information, Consider, sample size (n) =50 Provided 95% confidence interval = (18250,…

Q: With individual lines at its various windows, a post office finds that the standard deviation for…

A:

Q: Question 3 3. Suppose researchers calculated the 95% confidence interval to be (0.4145, 0.4675).…

A: As per guidelines we will solve the first question only, please repost other questions for more…

Q: b. With 95% confidence the population mean number of visits per week is between ____ and ____…

A: here given , n= 238  df = n-1  = 237  sample mean = 3.2  sample standard deviation  =  1.6

Q: Question 20. part C. Nationally, patients who go to the emergency room wait an average of 7 hours…

A: Given: Sample mean waiting time x¯= 5.8 Sample standard deviation (s)= 1.7 Sample size of patients…

Q: QUESTION 7 The annual report of a service company published that the average length of phone call of…

A: Question 7 The given sample size is 15, mean is 5.6 minutes, and standard deviation is 0.98.

Q: A fitness center is interested in finding a 90% confidence interval for the mean number of days per…

A: The random variable number of visits per week follows normal distribution. We have to construct the…

Q: Question 9 Given a sample of size 25 and an unknown standard deviation, which of the following…

A:

Q: If n=560 and p^ (p-hat) =0.8, find the margin of error at a 90% confidence level Give your answer…

A: Obtain the margin of error at 90% confidence interval.   The margin of error at 90% confidence…

Q: Question 16: If n=30, ¯xx¯(x-bar)=35, and s=20, construct a confidence interval at a 99% confidence…

A:

Q: QUESTION 17 Lena finds that, in a sample of 36 children, the mean age at which they first begin to…

A:

Q: A smart phone manufacturer is interested in constructing a 95% confidence interval for the…

A:

Q: QUESTION 1 Xona, a photocopy company plans to estimate the mean of visitors to its shop. There was a…

A: Given Standard deviation=σ=23 Confidence level=95% i.e. 100(1-alpha)%=95% Therefore, α=0.05 Allow…

Q: Suppose a sample of 200 local vendors is selected as part of a survey conducted by the Ministry of…

A: Givenn=200x=145

Q: Question 2: A polling company surveys the residents of a certain city (population 65,054) to…

A: Given: The sample number of residents are n=250. The number of people who approve the mayor are…

Q: Question 1. In a study of vehicle speeds on a certain section of highway, a simple random sample of…

A: Solution: Given information: n= 25 Sample size  x= 60.0 mph  Sample mean s= 4.0 mph Sample standard…

Q: Question 28 What test is used to compare two groups if the population standard deviation is unknown…

A:

Q: A random sample of n = 25 scores is selected from a population whose mean = 339 and standard…

A: Using Excel function =NORMSDIST()

Q: Question 10: A simple random sample of n=17 is drawn from a population that is normally…

A:

Q: A university wants to determine whether a recently hired instructor (Instructor I) is working out.…

A:

Q: QUESTION 30 Using basic demographic information (age, household income, marital status, etc.), you…

A: Given that,  a random sample size 184 customers who accepted a special balance transfer offer from a…

Q: QUESTION 1 Suppose that a survey was commissioned by the Ministry of Finance in order to determine…

A: Level of Significance: In testing of hypothesis, Level of Significance is the probability of…

Q: QUESTION 4 A report shows that the average cost of tuition and fees at a four-year university is…

A:

Q: QUESTION 1 Suppose a sample of 200 local vendors is selected as part of a survey conducted by the…

A: Given information n = 200 x = 145 p = 145/200 = 0.725 a) Error = 5% = 0.05 Confidence level = 0.97

Q: Question 8: After calculating a 98% confidence interval for the difference in populations means of…

A: Solution :- Given :- The difference in populations means of the weights of men and women in a…

Q: compute a 95% confidence interval for the average sleep of all college students.

A: Given Data : Sample Size, n = 500 Sample Mean, x̄ = 5.5 sample…

Q: Question 5 A consumer agency that proposes that lawyers' rates are too high wanted to estimate the…

A: Given Data : Sample Size, n = 70 Sample Mean, x̄ = 420 standard…

Q: Question 5: A simple random sample of 60 items resulted in a sample mean of 80. The population…

A: 5. a.

Q: QUESTION 1 The quality-control manager at a light bulb factory needs to determine whether the mean…

A:

Q: QUESTION 20 The manager of a paint store, wants to estimate the mean amount of a product sold per…

A: We want to find the lower confidence limit of 92% confidence interval

Q: QUESTION 9 If the population standard deviation is equal to 7.68 and the sample size is 117, what is…

A: Given : Population SD (σ) = 7.68 Sample Size (n) = 117 Confidence Level = 97% So ; significance…

Q: Grace Floral Shop claims that their average daily earnings is $497. An auditor wants to determine…

A: (a) Obtain the 97% confidence interval for the population mean daily earning. The 97% confidence…

Q: Illustration 18.1. The measured proport:on of success in a samplè of 25 is 0.5. (a) what is a 99%…

A:

Q: The length of a fully grown hibiscus plant is normally distributed and has a mean 35cm. It is found…

A:

Q: Question 3 A. The management of White Industries is considering a new method of assembling its golf…

A: 3 ( A ) We have given that  Sample size n = 24 Sample mean = 40.6 Standard deviation = 2.7 Note…

Q: Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the…

A: Sample size n = 14 Sample mean x = 5.8 hours Sample standard deviation s = 1.7 hours Nationally, the…