Which of the following is not an assumption of the Wilcoxon rank-sum test? Group of answer choices The data are ratio, interval, or ordinal in scale—all of which must be converted to ranked (ordinal) data before conducting the test. ​The underlying distribution is not normal. ​The observations are independent.

A printing company spends specific amounts on fixed costs every month. The costs of those fixed costs are in the table. Monthly fixed costs Monthly charges Bank charges Cleaning Computer expense Lease payments Postage Uniforms Monthly cost ($) 373 2691 2606 2580 2535 2165 Find the sample's mean, median, range, variance, and standard deviation using technology. Round to the nearest cent, if necessary. I The mean is The median is The range is The variance is The standard deviation is

An online math tutor service would like to claim that the average time spent taking a standardized test after students go through tutoring is less than the average time spent before going through tutoring. A simple random sample of students takes a pre-test, then goes through tutoring and takes a post-test. Results of the sample are shown below. Mean Variance Observations Pearson Correlation Hypothesized Mean Difference df t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail Confidence Level Before After 82.333 74.944 110.118 199.820 18 0.727 18 0 17 -3.227 0.002 -1.740 0.005 -2.110 99% What are the population parameters? Pick Is the two-sample hypothesis test a paired t-test or an unpaired t-test? Pick What is the level of significance? Ex: 0.12 What is the null hypothesis? Ho: Mafter Pick Mbefore What is the alternative hypothesis? Ha : Pafter Pick Should Ho be rejected or does Ho fail to be rejected? Pick What conclusion can be drawn from the data? Pick…

Choose the appropriate statistical test. When computing, be sure to round each answer as indicated. A dentist wonders if depression affects ratings of tooth pain. In the general population, using a scale of 1-10 with higher values indicating more pain, the average pain rating for patients with toothaches is 6.8. A sample of 30 patients that show high levels of depression have an average pain rating of 7.1 (variance 0.8). What should the dentist determine? 1. Calculate the estimated standard error. (round to 3 decimals). [st.error] 2. What is thet-obtained? (round to 3 decimals). 3. What is the t-cv? (exact value) 4. What is your conclusion? Only type "Reject" or Retain"

Histograms of random sample data are often used as an indication of the shape of the underlying population distribution. The histograms on the next page are based on random samples of size 30,50 and 100 from the same population. a. Using the midpoint labels of the three histograms, what would you say about the estimated range of population data from smallest to largest? Does the bulk of the data seem to be between 8 and 12 all in three histograms?  b. The population distribution from which the samples were drawn is symmetric and mound shaped, with the top of the mound at 10,95% of the data between 8 and 12, and 99.7% of data between 7 and 13. How well does each histogram reflect these characteristics?

Find the mean, the median, and all modes for the data in the given frequency distribution. (Round your answers to one decimal place. If there is more than one mode, enter your answer as a comma-separated list. If an answer does not exist, enter DNE.) mean      median      mode(s)      Points Scored by Lynn Points scored in abasketball game Frequency 2 9 6 8 7 9 10 7 11 2 13 4 14 2

Fill in the blanks. a. Positive correlations between observations of the response variable result in an underestimate of ________. b. Data collected from a designed experiment is generally preferable to data obtained from ________. c. Adata point whose removal has a substantial effect on one or more sample regression coefficients is called an _________.

Find the mean, the median, and all modes for the data in the given frequency distribution. (Round your answers to one decimal place. If there is more than one mode, enter your answer as a comma-separated list. If an answer does not exist, enter DNE.) mean      median      mode(s)      Points Scored by Lynn Points scored in abasketball game Frequency 2 8 8 5 9 8 13 4 14 1 18 3 21 1