For the following experiment, you will use the dataset BodyFat in the Sweeney Stats Group. Bodyfat...

For the following experiment, you will use the dataset BodyFat in the Sweeney Stats Group. Bodyfat was collected from a group of 252 CrossFit athletes. The average bodyfat for the American population is 23.4. Test the conclusion that the average bodyfat for Crossfit Athletes is less than the average bodyfat for the American population. Test using = .05. In addition to running the hypothesis test, answer the following question: Would you use this data to claim that CrossFit Athletes are in better shape than Americans? (Remember, lower body fat is better.)

Expert Solution

Assumed data,because not given in the data
sample mean, x =22
standard deviation, s =6
Given that,
population mean(u)=23.4

number (n)=252
null, Ho: μ=23.4
alternate, H1: μ<23.4
level of significance, α = 0.05
from standard normal table,left tailed t α/2 =1.651
since our test is left-tailed
reject Ho, if to < -1.651
we use test statistic (t) = x-u/(s.d/sqrt(n))
to =22-23.4/(6/sqrt(252))
to =-3.7041
| to | =3.7041
critical value
the value of |t α| with n-1 = 251 d.f is 1.651
we got |to| =3.7041 & | t α | =1.651
make decision
hence value of | to | > | t α| and here we reject Ho
p-value :left tail - Ha : ( p < -3.7041 ) = 0.00013
hence value of p0.05 > 0.00013,here we reject Ho
ANSWERS
---------------
null, Ho: μ=23.4
alternate, H1: μ<23.4
test statistic: -3.7041
critical value: -1.651
decision: reject Ho
p-value: 0.00013
we have enough evidence to support the claim that the average bodyfat for Crossfit Athletes is less than the average bodyfat for the American population.

orchestra answered 1 year ago

Activity 4: Experiment (YOU PRETEND TO DO THIS EXPERIMENT) The control group in an experiment is...

Activity 4: Experiment (YOU PRETEND TO DO THIS EXPERIMENT) The control group in an experiment is the group who does not receive any treatment and is used as a benchmark against which other test results are measured. A control group is used in an experiment as a point of comparison, so that it can be isolated in testing that the experiment did, or did not, have the intended effect. For example, scientists have developed many tests using reagents (substances used...

In this assignment, you will be required to use the Heart Rate Dataset to complete the...

In this assignment, you will be required to use the Heart Rate Dataset to complete the following: Identify the types of data represented by variables The range or types of values for each variable Give a brief written description of the variables, and how they are used in the data set. Steps Open the Heart Rate Dataset in Excel Identify each of the variables contained in the dataset by type Identify the type of data each variable represents (e.g., qualitative...

Open the Corn Yield dataset. There you see data recorded from an experiment to test 4...

Open the Corn Yield dataset. There you see data recorded from an experiment to test 4 organic pesticide methods (wasps, nematodes, pepper spray, and bacteria) to see if they eradicate corn weevils better than a standard chemical pesticide (control). For each method, effectiveness is determined by the average weight in grams of corn that is yielded from a randomly selected ear of corn. Use Minitab to do an Anderson-Darling test on the Yields to determine if the normality assumption for...

Consider the following dataset taken for a field experiment (meansure in meters) 120 230 220 305...

Consider the following dataset taken for a field experiment (meansure in meters) 120 230 220 305 410 250 290 300 200 210 210 200 210 210 300 400 200 210 350 3000 a. Describe the distribution by computing: i. Skweness. Interpret your result ii. Kurtoisis. Interpret your result b. is there an observation that may be an outlier? Explain? Draw a boxplot for the distribution

Challenge: Number Stats 2 Description: Extend the program you wrote for Number Stats to determine the...

Challenge: Number Stats 2 Description: Extend the program you wrote for Number Stats to determine the median and mode of the numbers read from the file. Purpose: The purpose of this challenge is to provide experience working with numerical data in a file and generating summary information including the determination of median and mode. It also provides experience adding new functionality to an existing program. Requirements: Extend the program you wrote for Number Stats to determine the median and mode...

How many structures can you find to use as a starting dataset if you wanted to...

How many structures can you find to use as a starting dataset if you wanted to study how proteins interact with DNA. Assume that you will require only high resolution structures for the study (at least 2.5 Angstroms resolution). For the study, you plan to use structures that were only solved by X-ray crystallography. (Select the closest number if the exact number is not available) * between 1000-1500 between 2700 - 4000 172 371 between 450 - 950 What is...

In an experiment like the one you will complete, a student collected the following data. Use...

In an experiment like the one you will complete, a student collected the following data. Use this information to complete the questions below. YOU MUST SHOW ALL CALCULATIONS. Change in Mass of Anode: -0.023 g Change in Mass of Cathode: +0.019 g Average Current: 38.7 mA Time of Electrolysis: 1860 s d) Using the average of the change in mass of copper from the electrodes in the electrolytic cell, calculate the molar mass of copper.

The morley dataset can be seen as a randomized block experiment with Run as the treatment...

The morley dataset can be seen as a randomized block experiment with Run as the treatment factor and Expt as the blocking factor. Is there a difference between runs and what efficiency is gained by blocking? Please solve using R. morley is a dataset in R. To access this dataset use: library(faraway) attach(morely)

a group of nonsmokers exposed to tobacco smoke (Summary Stats: n = 40, x = 60.58...

a group of nonsmokers exposed to tobacco smoke (Summary Stats: n = 40, x = 60.58 ng/mL, and s = 138.08 ng/mL) and a group of nonsmokers not exposed to tobacco smoke (Summary Stats: n = 40, x = 16.35 ng/mL, and s = 62.53 ng/mL). Use a 0.05 significance level to test the claim that nonsmokers exposed to tobacco smoke have a higher mean cotinine level than nonsmokers not exposed to tobacco smoke. (Assume the two samples are independent...

The IQ scores for a small group of stats students are: 90, 91, 89.25, 87.5, 89,...

The IQ scores for a small group of stats students are: 90, 91, 89.25, 87.5, 89, 90, 86, 92.8, 95, 88.3. Using the .01 significance level, how can I test the claim that stat students in general have IQ scores with a standard deviation that is 3 using the p- value method?

Question