Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Comparing operators of a DXA machine. Dual-energy X-ray absorptiometry (DXA) is a technique for measuring bone health. One of the most common measures is total body bone mineral content (TBBMC). A highly skilled operator is required to take the measurements. Recently, a new DXA machine was purchased by a research lab, and two operators were trained to take the measurements. TBBMC for eight subjects was measured by both operators. The units are grams (g). A comparison of the means for the two operators provides a check on the training they received and allows us to determine if one of the operators is producing measurements that are consistently higher than the other. Here are the data:
(a) Take the difference between the TBBMC recorded by Operator 1 and the TBBMC recorded by Operator 2. Describe the distribution of these differences.
(b) Use a significance test to examine the null hypothesis that the two operators have the same mean. Be sure to give the test statistic with its degrees of freedom, the P-value, and your conclusion.
(c) The sample here is rather small, so we may not have much power to detect differences of interest. Use a 95% confidence interval to provide a range of differences that are compatible with these data.
(d) The eight subjects used for this comparison were not a random sample. In fact, they were friends of the researchers whose ages and weights were similar to the types of people who would be measured with this DXA machine. Comment on the appropriateness of this procedure for selecting a sample, and discuss any consequences regarding the interpretation of the significance testing and confidence interval results.
How is the standard deviation of the data affected if there are disproportionately more 0s and 5s? Why can't we use the methods of this section to test that the last digits of the sample data have a standard deviation equal to 3?
The fracture toughness in concrete specimens is ameasure of how likely blocks used in new home construction may fail. A construction investigator obtains a random sample of 15 concrete blocks and determines the following toughness values: .47, .58..
Test hypothesis that two processes have identical fractions nonconforming. Use a = 0.05. Create the 90% confidence interval on difference in fraction nonconforming between two processes.
A game involving a pair of dice pays you 3 with probability 17/36, costs you 2 with probability 14/36, and costs you 4 with probability 5/36. What is your probability of losing money in one play of the game?
1. A certain store sells small, medium, and large toy trucks in each of the colors red, blue, green, and yellow. The store has an equal number of trucks of each possible color size combination. If Stella wants a medium, red truck and her mother wi..
What is the aim of multiple linear regression? Discriminate analysis? Canonical correlation? Multivariate analysis of variance?
compute the sample standard deviation of the following test scores 78787878.what can be said about a data set in which
The correlation between hours spent in the course and exam grades is .8. what percent f variation in exam grades can be explained by hours spent in the course?
the random variable x the time to failure in thousands ofmiles driven of the signal lights on an automobile has a
Create a five-number summary.- Draw a boxplot.- Draw your choice of a histogram, stem-and-leaf plot, or dotplot.
A random sample of 72 statistics students was taken to estimate the proportion of students who are also in the Math Club. The 90% confidence interval was 0.438 to 0.642. Using this information, what sample size would be necessary to estimate the t..
The population consists of two strata, H and L of sizes 100,000 and 500,000 and standard deviations 20 and 12 respectively. A stratified sample of size 100 is to be taken.
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd