Number of results: 11,441
The equally probable monetary results of a toss are +8,+7,-3, -3, -3 and -3. The expected result is (15-12)/6 = 0.50, a 50 cent gain. I assume you calculated the variance correctly also. The breakeven charge for a toss should be 50 cents. This is true regardless of the ...
Thursday, December 13, 2007 at 12:32am by drwls
at one high school the mean time for running the 100-yard dash is 15.2 seconds with a standard deviation of 0.9 seconds. The times are very close approximated by a normal curve. Find the percent of times that are: between 15.2 and 16.1 seconds
Monday, July 14, 2008 at 1:51pm by Leanne
First, relax 1) With your sample of 30, calculate the mean (average) travel time and the standard deviation. (I presume you know how to do these calculations). 2) Calculate the number of standard deviations that 45 minutes is away from the mean. That is X=(mean-45)/SD (mean ...
Sunday, December 16, 2007 at 4:05pm by economyst
You'll need to calculate the mean and standard deviation from your data. These values will be needed in the following formula: t = (sample mean - population mean)/(standard deviation divided by the square root of the sample size) Note: T-tests can be used for samples sizes 30 ...
Sunday, December 16, 2007 at 5:29pm by MathGuru
Background: A machine cuts wood boards to a thickness of 25 millimeters with an accepter margin of error of +/-0.6 ml. (Assume process can be distributed by normal distribution.) The acceptable range of thicknesses for the boards is 24.4 ml to 25.6 ml, inclusive. Because of ...
Monday, December 17, 2007 at 5:18pm by Brandon
The seasonal output of a new experimental strain of pepper plants was carefully weighed. The mean weight per plant is 15.0 pounds, and the standard deviation of the normally distributed weights is 1.75 pounds. Of the 200 plants in the experiment, how many produced peppers ...
Wednesday, December 19, 2007 at 9:34pm by Jenny
Using the normal approximation to the binomial distribution, let's look at the information given to you in the problem. Your values are the following: p = .01, q = 1 - p = .99, x = 10, and n = 1500 We need to find mean and standard deviation. mean = np = (1500)(.01) = 15 sd...
Monday, July 14, 2008 at 7:43am by MathGuru
Over the last 15 Major League Baseball seasons, the mean number of strikeouts by the American League leader is 258.5. Assuming that the number of strikeouts by the league leader is normally distributed and the standard deviation for all seasons in all leagues is 34.9, find the...
Friday, June 20, 2008 at 10:41pm by melanie
Probability of Mean (Statistics)
Assume 20 oz. cola bottles are filled so that the mean amount of liquid contained in the bottle is 20 oz and the standard deviation is .12 oz. If a case of 24 bottles is randomly selected from the population of all soda bottles, find the probability that the mean number of ...
Sunday, June 22, 2008 at 5:58pm by thomas
Statistics: 82% Confidence Interval
I'm having some difficulty with this problem: Over the last 15 Major League Baseball seasons, the mean # of strikeouts by the American League leader is 258.5. Assuming that the # of strikeouts by the league leader is normally distributed & the standard deviation for all ...
Sunday, June 22, 2008 at 4:54pm by melanie
Use a x squared-test to test the claim about the population variance or standard deviation at the given level of significance and using the given sample statistics. Claim: ơ2 ≤ 60; α = 0.025. Sample statistics: s2 = 72.7, n = 15
Wednesday, December 26, 2007 at 5:00pm by Brandon
Use a chi-squared test to test the claim about the population variance or standard deviation at the given level of significance and using the given sample statistics. Claim: ơ2 ≤ 60; α = 0.025. Sample statistics: s2 = 72.7, n = 15
Thursday, December 27, 2007 at 11:37am by Brandon
Statistics: 82% Confidence Interval
Here's the formula I would use for this type of problem: CI82 = mean + or - 1.35(sd / √n) ...where + or - 1.35 represents the 82% confidence interval, sd = standard deviation, √ = square root, and n = sample size. With your data: CI82 = 258.5 + or - 1.35 (34.9 / ...
Sunday, June 22, 2008 at 4:54pm by MathGuru
This appears to be a hypothesis test involving inferences concerning two variances (standard deviation is the square root of the variance). Sample 1: n = 25; variance = sd^2; df = n - 1 = 24 Sample 2: n = 25; variance = sd^2; df = n - 1 = 24 Note: sd = standard deviation. Test...
Thursday, June 19, 2008 at 5:22am by MathGuru
OK, I will try but I am no expert and have not looked at this material for years. a)80/720 = .111... = 11.1% What is the probability of finding more than 11.1% defective? sigma , the standard deviation of p is sqrt(.15*.85)/sqrt(720) = sqrt(.1275)/sqrt(720) =.35355/26.83 sigma...
Sunday, January 13, 2008 at 7:05pm by Damon
I think you can calculate the Z-scores for yourself. The Z-score assumes a normal distribution, taking into account the mean and standard deviation. From calculus, we know the proportions/percentages in the normal distribution. (See a table in the back of your statistics text...
Wednesday, July 9, 2008 at 9:06pm by PsyDAG
at a bank, account balances are nomrally distribued with a mean of $637.52 and standard deviation of $623.16. What is the probability that a simple randon same of 400 accounts has mean that exceeds $1650.00? show me steps and calculations i urgently need help
Wednesday, January 23, 2008 at 8:29pm by son
For a particular sample of 50 scores on a psychology exam, the following results were obtained. Mean = 78 Midrange = 72 Third quartile = 94 Mode = 84 Median = 80 Standard deviation = 11 Range = 52 First quartile=68 What score was earned by more students than any other score? ...
Thursday, January 24, 2008 at 8:17pm by Jennifer
Calculate SS, variance, and standard deviation for the following sample of n=9 scores:2,0,0,0,0,2,0,2,0.(Note: The computational formula for SS works best with these scores.) I keep getting the wrong numbers. Thank You.
Tuesday, January 29, 2008 at 6:47pm by Tracy
sample- a recent study reports that older adults who got regular physical exercise experienced fewer symptoms of depression, even when tested 2 years late. regular excersize scores= 1,3,4,3,5,2,3,4 no regular excersize scores=5,4,6,3,5,7,6,6 a)calculate the mean and the ...
Wednesday, January 30, 2008 at 6:16pm by Byron