Purchase Solution

Distribution of sample average, variability of distribution

Not what you're looking for?

Ask Custom Question

Suppose investigators are interested in a population of patients who have been recently diagnosed with a particular kind of colon cancer (nonpolypoid colorectal neoplasm). They believe the diameter of the colon cancer lesion at first diagnosis in this particular population is 15.9mm with standard deviation 10.2mm . Let x= lesion diameter for a patient with colon cancer at first diagnosis.
Investigators select a sample 165 patients at random from this population and calculate the average lesion diameter, x , for the sample.

8. How is the sample average, x , distributed? Choose the most likely answer:
a) the distribution of x is exactly binomial
b) the distribution of x is approximately binomial
c) the distribution of x can't be determined unless we know that x is distributed normally
d) the distribution of x is approximately normal
e) the distribution of x must be the same as the distribution of x

9. Which of the following is true, concerning the variability of the distribution of x (the individual lesion diameter) and the distribution of x (the average lesion diameter in the sample)?
a) x (the individual lesion diameter) varies less than x (the average lesion diameter)
b) x (the individual lesion diameter) varies more than x (the average lesion diameter)
c) x (the individual lesion diameter) varies about the same as x (the average lesion diameter)
d) we need more information to determine which (x or x ) varies more

Purchase this Solution
Solution Summary

Answers questions on Distribution of sample average, variability of distribution.

Solution Preview

Suppose investigators are interested in a population of patients who have been recently diagnosed with a particular kind of colon cancer (nonpolypoid colorectal neoplasm). They believe the diameter of the colon cancer lesion at first diagnosis in this particular population is 15.9mm with standard deviation 10.2mm. Let x= lesion diameter for a patient with colon cancer at first diagnosis.
Investigators select a sample 165 patients at random from this population and calculate the average lesion diameter, x, for the ...

Purchase this Solution
Free BrainMass Quizzes
Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

View More Free Quizzes
Related BrainMass Solutions

  • Parameter estimation: bias and variability

    When the variance of the distribution of sample statistics is reduced, the difference between the parameter and the statistic is, on average, smaller when the procedure is used a large number of times.

  • Standard scores, measures of variability, & norms

    The bigger the standard deviation of a sample, the more variability (difference in scores) there is between people in the sample.

  • Frequency distribution and statistical analysis

    The Frequency Distribution of Sample A indicates that the variability of sample jewel cases spans a distance 0.6 mm.

  • RES 341 Multiple-Choice Questions

    What is also referred to as the "midpoint" in a set of scores? a. Average b. Mean c. Mode d. Median 15. What is the term associated with scores that are at the extreme ends of the distribution? a. Variability b. Outliers c. Skew d.

  • Difference Between t statistic and z statistic

    The reason the t-distribution has more variability is because there are 2 random variables accounted for (s and xbar) as opposed to the z-distribution which only has one (xbar). Please see the attachment for more details.

  • Normal Distribution, Sampling distribution

    (C) measures the variability of the mean from sample to sample (D) All of the above 10) When determining the sample size for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimate to be, the _____the

  • Hypothesis for difference in the variances: F distribution

    What is the critical value of the F distribution? Perform the test at the .05 level of significance. What is the observed value of the F distribution? What are your conclusions? Please see the attached file.

  • Sample size calculation

    244702 Solving a sample size calculation problem How does the bell-shaped curve for the sampling distribution of sample means for samples of size n = 120 compare to the bell-shaped curve for the sampling distribution of sample means for samples of size

  • independent t test versus paireed t test

    The whole point of using a paired experimental design and a paired test is to control for experimental variability.

View More Related Solutions