
Mathematics
The standard deviation of given population is 4.5 with a mean of 60 and the refit population has a standard deviation of 5.2 with a mean of 75. Calculate the coefficient of variation for both populations and comment on the results.
asked by Ray on July 22, 2011 
Math
The mean of a sample of 25 was calculated as xbar = 500. The sample was randomly drawn from a population whose standard deviation is 15. Estimate the population mean with 99% confidence. B.) Repeat part (a) changing the population standard deviation to 30.
asked by Joe on April 27, 2010 
statistics
How do we compute sample size fluctuations? Suppose we have a population of 16000 and a sample size of 30, and the number of samples 1000, what will be the impact on population mean and standard deviation when the population is normally distributed? When
asked by Nasir on December 1, 2011 
sample size/ standard deviations
How do we compute sample size fluctuations? Suppose we have a population of 16000 and a sample size of 30, and the number of samples 1000, what will be the impact on population mean and standard deviation when the population is normally distributed? When
asked by ut on December 1, 2011 
Math (Statistic)
Considered the sampling distribution of a sample mean obtained by random sampling from an infinite population. This population has a distribution that is highly skewed toward the larger values. a) How is the mean of the sampling distribution related to the
asked by Jennifer on February 19, 2007 
Statistics
In an essay of 250500 words, thoroughly address the following items and respond to the related questions: 1.Define the term standard deviation. Why is it important to know the standard deviation for a given sample? What do researchers learn about a normal
asked by Andrew on January 23, 2014 
statistic
1. A distribution has a standard deviation of 12. Find the zscore for each of the following locations in the distribution. a. Above the mean by 3 points. b. Above the mean by 12 points. c. Below the mean by 24 points. d. Below the mean by 18 points.
asked by Nickie on January 26, 2013 
statistics
what are the mean and standard deviation of a sampling distribution consisting of samples of size 16? these sameples were drawn from a population whose mean is 25 and who standard deviation is 5. a. 25 and 1.25 b. 5 and 5 c. 25 and 5 d. 5 and 1.25 e. 25
asked by helga on February 1, 2009 
math
Can I gt some help on these questions! 1.Research subjects that are divided up based on gender, age, etc. to be compared to people of the same group is what type of design experiment? 2. A biologist collects a sample of 50 snakes. The snakes have a mean
asked by mysterychicken on June 20, 2013 
statistics
Given a sample size of 38, with sample mean 660.3 and sample standard deviation 95.9 we are to perform the following hypothesis test. Null Hypothesis H0: ƒÊ = 700 Alternative Hypothesis H0: ƒÊ ‚ 700 At significance level 0.05 3. Calculate the test
asked by Scott on August 9, 2010 
Statistics
This is the first question..... For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3. This is the second question....For each of the following samples that were given an
asked by Heather on May 3, 2011 
statistics
A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. The population mean is 8. 2. Identify the
asked by Cameron on June 3, 2013 
Statistics
A population has a mean of 30 and a standard deviation of 5. a. If 5 points were added to every score in the population, what would be the new values for the mean and standard deviation? b. If every score in the population were multiplied by 3 what
asked by Nickie on January 26, 2013 
math
The standard deviation of a sample taken from population A is 17.6 for a sample of 25. The standard deviation of a sample taken from population B is 21.2 for a sample of 30. The standard deviation of the sample mean differences is_____. (Round your answer
asked by j on July 15, 2015 
Statistics
hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard deviation and mean. for
asked by ash on November 21, 2010 
math
hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard deviation and mean. for
asked by ash on November 21, 2010 
stats
A sample of 12 observations is selected from a normal population for which the population standard deviation is known to be 4. The sample mean is 19. (Round your answers to 3 decimal places.) (a) The standard error of the mean is The 90 percent confidence
asked by liam on March 28, 2011 
math
sample of 40 observations is selected from one population with a population standard deviation of 4.6. The sample mean is 101.0. A sample of 47 observations is selected from a second population with a population standard deviation of 4.0. The sample mean
asked by Phyllis on February 2, 2015 
Statistics
The null and alternate hypotheses are: H0: μ1 = μ2 H1: μ1 ≠ μ2 A random sample of 15 items from the first population showed a mean of 50 and a standard deviation of 5. A sample of 12 items for the second population showed a mean of 46 and a standard
asked by Anonymous on October 21, 2012 
statistics
sigma is the standard deviation of a population of size N S is the standard deviation of a sample of size n from within the population. What is the estimated value of S^2? If the population was infinitely large (size N = infinity), what would the estimated
asked by mathstudent on February 21, 2008 
statistics
Describe the major difference between a population of scores with a mean=50, standard deviation=6, and a sample means of n=36 selected from a mean=50, standard deviation=6.
asked by Nneka on March 9, 2011 
Stats
You take and SRS of size 25 from a population with mean 200 and standard deviation of 10. Find the mean and the standard deviation of the sampling distribution of your sample mean.
asked by Ryan on July 14, 2011 
Psychology/Statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size  3. Use the formula sqrt(N^ 2/S)
asked by Dawn on July 15, 2011 
statistics
A researcher administered a treatment to a sample of participants selected from a population of 80. If the researcher obtains a sample mean of M=88. Which combination of factors is most likely to result in rejecting the null hypothesis? a, alpha level=0.01
asked by Robbie on November 9, 2012 
Statistics
You have a population that has a mean of 100 and a standard deviation of 15. You randomly draw 100 people out of this population and record the mean score. You repeat the process a large number of times recording the mean score for each sample you draw.
asked by Jared on October 14, 2012 
Behavioral Statistics
You have a population that has a mean of 100 and a standard deviation of 15. You randomly draw 100 people out of this population and record the mean score. You repeat the process a large number of times recording the mean score for each sample you draw.
asked by Jared on October 14, 2012 
statistics
it is stated that the standard deviation sample of the is 7.6 (n = 26). Test the claim to a significance level of 0.10 that the population standard deviation was greater than 7.0. Round all answers to 3 decimal places.
asked by geety on July 28, 2012 
statistics
it is stated that the standard deviation sample of the is 7.6 (n = 26). Test the claim to a significance level of 0.10 that the population standard deviation was greater than 7.0. Round all answers to 3 decimal places.
asked by geety on July 28, 2012 
statistics
An SRS of size n is taken from a large population whose distribution of income is extremely rightskewed and the mean income is calculated. Which of the following statements is false? a) When n > 30, the sampling distribution of is approximately normal. b)
asked by Anna on April 17, 2012 
Stat
An SRS of size n is taken from a large population whose distribution of income is extremely rightskewed and the mean income is calculated. Which of the following statements is false? a) When n > 30, the sampling distribution of is approximately normal. b)
asked by Sam on May 6, 2016 
Statistics
If the standard deviation of a population is 56 and we want the standard error (the standard deviation of the sample mean) to be 14, then we need to take how many samples?
asked by Jana on December 20, 2010 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size  (b) 3 ?.
asked by net on February 13, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by mama on April 10, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by kim on January 24, 2011 
stATS
the standard deviation of the sampling distribution of the means is ____the standard deviation of the population under study.
asked by tim on November 4, 2011 
Statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3.
asked by Barbara on November 15, 2010 
Statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by Felicia on November 19, 2010 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3
asked by amanda on April 4, 2011 
psychology
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size  (b) 3 ?.
asked by net on February 13, 2011 
statistics
population has mean 53 and standard deviation 12. Calculate the standard deviation of x bar for a random sample of size 12.
asked by Bridget on August 18, 2014 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by Mae on May 12, 2011 
Statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size: 3
asked by Christy on July 4, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3
asked by melissa on January 10, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by Anonymous on January 30, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3.
asked by Reba on June 14, 2011 
statistics
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3.
asked by hope on June 13, 2011 
psy325
For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size (b) 3
asked by smith on December 15, 2010 
Statistics
How do you figure this out? For a population that has a standard deviation of 10, what is the standard deviation of the distribution of means for samples of size 2? A6.33 B7.07 C2 D3.03
asked by Amanda on May 7, 2010 
statistics
For a population that has a standard deviation of q0, figure the standard deviation of the distribution of means for samples of size(a)2,(b)3,(c)4,(d)9.
asked by Dorothy on July 6, 2011 
Math1(Please Help Me)
A group of 894 women aged 7079 had their height and weight measured. The mean height was 159 cm with a standard deviation of 5 cm and the mean weight was 65.9kg with a standard deviation of 12.7kg. Both sets of data are fairly normal. A.) Suppose you were
asked by Candice on June 21, 2016 
Statistics
For sample mean x = 150, sample size n = 36 and sample standard deviation s = 40 find 80% confidence interval for population mean. Population standard deviation is not known
asked by Tina on February 24, 2012 
college math
Math homework please help!! 2. Suppose that people’s weights are normally distributed, with mean 175 pounds and a standard deviation of 6 pounds. Round to the nearest hundredth of a percent a. What percent of the population would weigh between 165 and
asked by lynda on November 5, 2013 
math
Four boxes of cereal are to be selected at random from a continuous process that fills boxes labeled "Contents: 340 g." The contents of the first three boxes are found to weigh 339.0g, 337.7 g, and 338.9 g. (a) What minimum weight of cereal must the fourth
asked by david on September 23, 2012 
Statistics
1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per
asked by Anonymous on May 9, 2013 
probs & stats
1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per
asked by adrenning on May 11, 2015 
statistics
poppulation with a mean=100,standard deviation population=10, and n=40. 1) find mean of all values in apoplution. 2) find standard deviation population 3) p(82 LESS THAN 82 less than 97 find mean)
asked by Anonymous on October 21, 2010 
Statistics
The t distribution should be used when ___. the sampling population is not normal the sampling population is unimodal The sampling distribution is normal and the population standard deviation is unknown the population standard deviation is known
asked by John on June 22, 2010 
Statisitcs
The mean height of fully grown birch trees are 18 feet with a standard deviation of 1.2 feet, normally distributed. Random samples of size 9 are drawn from this population and the mean of each sample is determined. Find that mean and the standard error of
asked by D on November 14, 2012 
Algebra
Use a calculator to find the mean and standard deviation of the data. Round to the nearest tenth. 6,7,19,7,18,7 A. mean = 9; standard deviation = 26.4 B. mean = 11.9; standard deviation = 26.4 C. mean = 10.6; standard deviation = 6.1 D. mean = 9; standard
asked by Veronika on February 18, 2016 
business statistics
A sample of 40 investment customers serviced by an account manager are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A sample of 30 customers serviced by another account manger averaged
asked by Heidi on August 4, 2009 
Stats
I just need help with starting how to calculate the problem I am so lost. A random sample of eight observations from the first population resulted in a standard deviation of 10. A random sample of six observations from the second population resulted in a
asked by Yasmin on December 6, 2010 
Statistics/Probability
The standard deviation of the masses of articles in a large population is 4.55 kg. Random samples of size 100 are drawn from the population. Find the probability that a sample mean will differ from the population mean by less than 0.8 kg.
asked by Koylar on July 17, 2014 
statistics
A sample of 40 observations is selected from one approximately normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean is 99 and the standard deviation
asked by K on May 22, 2010 
statistics
A sample of 40 observations is selected from one approximately normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean is 99 and the standard deviation
asked by georgia on May 29, 2010 
statistics
5) The lifetime of a medical device s a normally distributed rv with standard deviation of 2 years. An experiment is conducted to test 15 medical devices and find their lifetimes to be: a. If the population mean is known to be 15 years, what is the
asked by nur on December 8, 2012 
statistics
What is the formula to do this exercise, Please. A sample of 40 investment customers serviced by an account manager are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A sample of 30
asked by Maggy on August 9, 2009 
business statistics
Please can you give the formula please, A sample of 40 investment customers serviced by an account manager are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A sample of 30 customers
asked by Heidy on August 9, 2009 
Statistics
Suppose that a sample of size 60 is drawn from a population with mean 73 and standard deviation 79. Find the value of , the standard deviation of the distribution of sample means. How do I work this on my calculator?
asked by Anonymous on June 18, 2013 
Statistics
QUESTION 1 Use the following scenario and data for all the questions The lives of Lithium batteries used in a type of cell phones are normally distributed with an unknown standard deviation. A simple random sample of equation batteries is selected. The
asked by Neyra on October 31, 2017 
business statistics
Please can you give the formula to do this exercise, Thank you. A sample of 40 investment customers serviced by an account manager are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A
asked by Heidy on August 10, 2009 
Statistics
A college statistics class conducted a survey of how students spend their money. They asked 25 students to estimate how much money they typically spend each week on fast food. They determined that the mean amount spent on fast food is $31.52 with a
asked by sam on October 14, 2016 
statistics
A sample of 40 CDs from a student's collection showed a mean length of 52.74 minutes with a standard deviation of 13.21 minutes. Construct a 95% confidence interval for the population standard deviation. (Round your answers to 4 decimal places.)
asked by Anonymous on June 26, 2014 
Math
Roughly speaking, the standard deviation indicates how far, on average, the observations are from the mean. Do you think that for the data set below the standard deviation will give a good indication of the typical deviation from the mean? 2, 3, 4, 4, 5,
asked by Lyndse on February 21, 2010 
stats
The president of a large university wishes to estimate the average age of the students presently enrolled. From past studies, the standard deviation ó is known to be 2 years. A sample of 50 students is selected and the mean is found to be 23.3 years. a.
asked by chris on April 7, 2013 
Psychology
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test (with an estimated
asked by Anonymous on September 23, 2010 
Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard deviation of 5).
asked by Anonymous on October 10, 2009 
MathStatistics
Two questions that I'm unsure of are below: 1). The variability of a statistic is described by: a) the spread of its sampling distribution. b) the amount of bias present c) the vagueness in the wording of the question used to collect the sample data d) the
asked by Anonymous on March 15, 2011 
Statistics
I have a question that involves explaining what is wrong in each of the following situations: (a) A random sample of size 20 is taken from a population that is assumed to have a standard deviation of 12. The standard deviation of the sample mean is 12/20.
asked by Lynn on March 29, 2009 
Psychology
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test (with an estimated
asked by summer on September 19, 2011 
Statistics
1) A Motor Company has purchased steel parts from a supplier for several years and has found that 10% of the parts must be returned because they are defective. An order of 25 parts is received. What are the mean and standard deviation of the defective
asked by BEARHUG on February 15, 2009 
statistics
A population has a mean =80 and a standard deviation =8. find the mean and standard deviation of a sampling distribution of sample means with sample size=64
asked by antorio on February 12, 2013 
statistics
a population has mean 15 and standard deviation 5. if 68% of the values in the population are between 10 and 20, the population cannot be normal
asked by nikki on July 11, 2011 
statistics
Consider the test of hypothesis for the equality of two population means. The sample data from the first population is: n = 10, xbar = 52.4, s = 5. The sample data from the second population is: n = 8, xbar = 48.2, s = 6. Both variables are normally
asked by Anonymous on March 27, 2015 
statistics
A statistics practitioner would like to estimate a population mean to within 50 units with 99% confidence given that the population standard deviation is 250. a) What sample size should be used. b) Repeat part (a) with a standard deviation of 50. c) Repeat
asked by Tom on March 13, 2010 
statistics
A study found that citizens spend on average $1950 per year on groceries with a standard deviation of $100. Assume that the variable is normally distributed. 5. Identify the population mean. 6. Identify the population standard deviation. 7. Find the
asked by Cam on April 19, 2013 
statistics
Assume the population distribution of FEV is normal with standard deviation 400 mLi. (a) find P(E) is n=15 and population mean is 2800 mLi (B) find P(E) is n=15 and the population mean is 2600mLi (C) How does P(E) depend on the population mean?
asked by Sam on October 13, 2009 
Statistics
If the standard deviation of a sample is 4.3 for 28 data values, what would the standard deviation be fore the population from which the sample was drawn?
asked by Leisa on January 30, 2013 
Math
Repeated sample of 36 are drawn from a population with mean 52 and standard deviation 18. What is the standard deviation of the distribution of the sample means?
asked by Lori on March 28, 2011 
statistics
You want to determine if your widgets from machine 1 are the same as machine 2. Machine 1 has a sample mean of 5 and a population standard deviation 1 and a sample size of 4. Machine 2 has a sample mean of 8 and a population standard deviation of 2 with a
asked by Anonymous on October 11, 2010 
STAT
You want to determine if your widgets from machine 1 are the same as machine 2. Machine 1 has a sample mean of 5 and a population standard deviation 2 and a sample size of 4. Machine 2 has a sample mean of 10 and a population standard deviation of 2 with a
asked by Tammy on October 7, 2013 
statistics
A statistics practitioner formulated the following hypothesis: Ho: population mean=200 H1: population mean
asked by Adam on March 19, 2010 
Business
For a continuous random variable x, the population mean and the population standard deviation are 80 and 15 respectively. You extract a sample of 25 elements from this population. The mean of the sampling distribution of the sample mean is
asked by Donna on May 16, 2010 
Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard deviation of 5).
asked by Anonymous on October 11, 2009 
statistics
An IQ test was administered to a random sample of 26 mental patients and the mean was found to be 99.7. For this test, the population values are known to be normally distributed and with a population standard deviation of 15. Construct a 90% confidence
asked by Anonymous on December 18, 2014 
math
A medical researcher wants to determine whether male pulse rates vary more or less than female pulse rates. Using the sample pulse rates in Data Set 1 in Appendix B, the male pulse rates can be summarized with the statistics 40=n,69.4=x,11.3=s. For
asked by josh on November 27, 2017 
statistics
Suppose a population distribution of SAT scores has population mean 500 and population standard deviation 100. What is the mean of the sampling distribution of sample means, ybar , calculated from samples of size n = 36
asked by Emmily on November 11, 2011 
statistics
A sample of 25 men has a mean weight of 65kg with standard deviation of 8kg. Suppose that the weight of men follows normal distribution with a standard deviation of 10kg. Find a 95% confidence interval for the population mean μ.
asked by Ali on June 3, 2011 
Statistics
Scores on an IQ test are normally distributed. A sample of 15 IQ scores had standard deviation s=10. The developer of the test claims that the population standard deviation is =15. Do these data provide sufficient evidence to contradict this claim? Use
asked by steph on March 12, 2019 
statistics
How large a sample should be taken if the population mean is to be estimated with 99% confidence to within $75? The population has a standard deviation of $900.
asked by Kabelo on April 15, 2018 
statistics
How large a sample should be taken if the population mean is to be estimated with 99% confidence to within $72? The population has a standard deviation of $800.
asked by Kennon on November 18, 2008
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