Researchers want to know if a new fuel treatment leads to a change in the mean fuel usage of a certain car. To test this, they conduct an experiment in which they measure the fuel usage (litres per km) of 11 cars with and without the fuel treatment. Which hypothesis test is appropriate? a) chi-squared test b) one sample t-test c) two sample t-test d) t-test of differences e) one sample t-test of slope

instructor thinks that the mean score is higher. She samples 10 statistics students and obtains the scores: Grades 63.9 68.4 | 69 | 96 64.3 | 63.9 65 69 62.7 68.4 Test grades are believed to be normally distributed. Use a significance level of 5%. A. State the alternative hypothesis: HA: Ou + 65 Ομ 65 B. State the mean of the sample: C. State the standard error of the sample means:

Only answer the questions typed: A. indicate whether it's one or two sidedB. Indicate whether it's a test of means or proportionsC. Write out the expression for determining the P-value

An instructor wanted to know if his students are better at math or writing. He had students take both a math and then a writing test and he compared the results using SPSS. He found the following results: ( look at graphs )  a. What test was done?b. Report results in APA style.

Consider full-time community college students as an observational unit. a) Come up with one categorical and one quantitative variable related to a full-time community college student.  [You CANNOT use AGE, HEIGHT, GENDER, MAJOR].  b) Considering your categorical variable from part a), name three types of graphical displays you can use to represent that variable.  c) Come up with one quantitative variable for a community college student that would have a distribution that is SKEWED RIGHT or SKEWED LEFT.

A college administrator wants to know if there is a significant difference between sexual orientation and level of family support for students at their college. The administrator takes a random sample of students who identify as gay/lesbian, bisexual or heterosexual/straight. There were 22 students sampled in each category. A measure of family support is given with higher scores indicating more family support. The means are as follows: Gay/lesbian Bisexual Heterosexual/Straight MG/L = 16 MBi = 17 MH/S = 22   Source SS df MS F Orientation 300       Error 2961       Total           What is the value of df total?

AFDA Main Ideas: Module 9 Review 1) The measures of center: 2) Measures of spread: 3). When describing a data set, the mean is used with used with 4) Z-scores are used to compare data that is 5). What is the formula for finding the z-score? 14 6). The z-score of the mean is always z = 7). What are the characteristics of a normal distribution? and and and the median is 8). What two characteristics make a distribution go from "normal" to "standard normal?"

researchers wanted to determine if carpeted rooms contained more baterica than uncapted rooms. to determine the amount of bacterica in a room reseachers pumpled the air from the room over a petri dish at the rate of 1 cubic foot per minute for eight carpeted rooms and eight uncaprted rooms. colonies of baterica were alled to form in 16 petri dishes. the results shown below are the baterica counta per cubic foot   mean standard deviation  sample size    capeted room  11.2 2.6774 8   uncapted room  9.7875 3.21 8   you want ti test using sigificance level of 0.01 whether the mean bactiria count is high for carpeted rooms than for uncapteed rooms. test whether the mean bacteria count is high for carpeted rooms thatn uncarpeted rooms. show all steps using the p value method.   what is Ho and H1? what is the test statsic and p value? what conclusion can be made?

The table below shows the distribution of weight of a certain type of fruit. weight frequency <10 4 <15 3 <20 23 <25 54 <30 16 <35 9 <40 7 <45 4 1) Draw the histogram of the data and use it to estimate the model weight. 2) calculate mean, median and interquartile range.

a study of store checkout​ scanners, 1234 items were checked and 23   checked items were overcharges. Use a 0.05 significance level to test the claim that with​ scanners, 1% of sales are overchanrges.​ (Before scanners were​ used, the overcharge rate was estimated to be about​ 1%). a. Define the parameter     A. mu   ​= The proportion of all sales that are undercharges   B. p​ = The proportion of all sales that are incorrect   C. p​ = The proportion of all sales that are overcharges   D. mu   ​= The mean number of sales that are overcharges   b. State the null and alternative hypotheses     A. Upper H 0 : mu not equals 0.01 Upper H 1 : mu equals 0.01     B. Upper H 0 : p greater than 0.01 Upper H 1 : p equals 0.01     C. Upper H 0 : p equals 0.01 Upper H 1 : p not equals 0.01     D. Upper H 0 : p equals 23    Upper H 1 : p less than 23     c. Calculate the sample proportion ModifyingAbove p…