Recent Homework Questions About Statistics
A random sample of 100 students from a high school was selected. If a 98% confidence interval estimate for the mean age of students is calculated to be 14.2511 to 14.9489, then the standard deviation of the sample mean is?
Sunday, November 17, 2013 at 10:54pm
A management consultant has analysed a random sample of 40 large firms in order to investigate the mean annual salary of sales managers. She has constructed the following 90% confidence interval for the population mean annual salary: $45,382 to $48,618. In testing the ...
Sunday, November 17, 2013 at 10:53pm
Sunday, November 17, 2013 at 5:08pm
How large a sample would be needed to form a 90% confidence interval for the mean nicotine content of a brand of cigarettes if the nicotine content has a normal distribution with sigma equal to 8.5 mg and the width of the interval (the length of the confidence interval) equal ...
Sunday, November 17, 2013 at 12:56pm
A credit manager has chosen a sample of size 2,164 to estimate the mean balance of credit accounts to within $0.50. A pilot study of 50 accounts had a mean of $1,219 and a variance of 100. The level of confidence of the interval is: 90% ? 95% ? 98% ? 99% ?
Sunday, November 17, 2013 at 12:25pm
618-+2.575*11.7/sqrt((40)) = (, )?
Sunday, November 17, 2013 at 12:19pm
x d=(x -x bar) (x -x bar)^2 2 -1.2 1.44 6 2.8 7.84 4 .8 0.64 3 0-.2 0.04 1 -2.2 4.84 d bar = 3.2 ∑(x-d bar)^2 =14.8 sd = sqrt((14.8/4)) = 1.92 t = 3.72 p-value = 0 .9898 Degree of freedom = n -1 = 4 Since the computed value of t is less than the table value of t we ...
Sunday, November 17, 2013 at 7:41am
a, b. No inferences being made. c. There is no data for other nights, so this is an inference.
Saturday, November 16, 2013 at 10:44pm
Saturday, November 16, 2013 at 10:42pm
oops typo, In the following question, identify which choices would be considered descriptive statistics and which would be considered inferential statistics.
Saturday, November 16, 2013 at 8:55pm
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See your later post.
Saturday, November 16, 2013 at 8:53pm
Proportion = # in category/total number
Saturday, November 16, 2013 at 10:37am
When you have specific data, it is descriptive. When you go outside the actual data, it is inferential. 1. a, b and c infer. 2. a describes, b and c infer.
Thursday, November 14, 2013 at 12:11pm
Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities related to the Z scores. Reverse process with last question, starting with .90.
Thursday, November 14, 2013 at 12:13am