Statistics
posted by Jake .
Check my answers please!
Thanks a lot.
Five students reported that the previous night they slept: 7,8,7,10,9 hours.
Calculate the sample varience and standard deviation.
sample varience = 1346.5
standard deviation = 36.7
Consider this. Ths standard deviation can never be larger than the range of scores. Assuming that you are still talking in hours, you answer is much larger.
mean = 8.2
Differences obtained by subtracting the score from the mean =
1.2
.2
1.2
1.8
.8
Squaring each of these gives you
1.44
.04
1.44
3.24
.64
Totaling 6.8. Dividing this by N (5) gives you 1.36 = variance
The square root of the variance is the standard deviation.
I hope this helps. Thanks for asking.
Respond to this Question
Similar Questions

Statistics: Sample Size, Variance and Standard Dev
Sample Size, Variance and Standard Deviation A student organization plans to ask 100 randomly selected students how much they spent on textbooks last semester. You argue for a sample of 900 students instead of 100. You know the standard … 
statistics
what are the mean and standard deviation of a sampling distribution consisting of samples of size 16? 
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 … 
statistics
The mean length of a work week for the population of workers was reported to be 39.2 hours. Suppose that we would like to take a current sample of workers to see whether the mean length of a work week has changed from the previously … 
statistics
In a random sample of 50 babies 4 to 7 month old the average number of hours they slept per day turned out to be 14.2 hours with a standard deviation of 1.6 hours find and interpret a 90% confidence interval for the mean number of … 
statistics
In a random sample of 50 babies 4 to 7 month old the average number of hours they slept per day turned out to be 14.2 hours with a standard deviation of 1.6 hours find and interpret a 90% confidence interval for the mean number of … 
AP Statistics
A school psychologist reports that the mean number of hours the students at this school sleep each night is 8 hours. The students believe the mean is not 8 hours. To find an estimate of the true mean, they select a random sample of … 
statistics
It has been reported that 86% of federal government employees use email. If a sample of 175 federal government employees is selected, find the mean, varience, and standard deviation of the number who use email. 
Statistics
A sample of 12 measurements has a mean of 37 and a standard deviation of 4.25. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 37 each. A. Find the mean of the … 
Statsistics
You are testing the claim that the mean GPA of night students is less than the mean GPA of day students. You sample 45 night students, and the sample mean GPA is 2.18 with a standard deviation of 0.31 You sample 30 day students, and …