Using R-Studio software, carry out relevant tests to determine if the assumptions of normality and  homogeneity of variance were violated. Discuss the results using relevant statistics and provide the necessary hypotheses. (Provide the code used only)

An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 7.4 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 280 engines and the mean pressure was 7.5 pounds/square inch. Assume the variance is known to be 0.81. A level of significance of 0.05 will be used. Make a decision to reject or fail to reject the null hypothesis. Make a decision. Answer O Reject Null Hypothesis O Fail to Reject Null Hypothesis Tables: Keypad Keyboard Shortcut

Students in one class are asked to complete the same questionnaire 3 times throughout the semester: at the beginning, at the midterm, and at the end. The purpose of the questionnaire is to track students' perception of their progress at different points in the semester. Scores at Time 1 (beginning of the semester), Time 2 (midterm), and Time 3 (end of semester) are compared against one another. What type of analysis of variance would be appropriate for examining the results from this dataset?

The accompanying data table contains chest deceleration measurements (in g, whereg is the force of gravity) from samples of small, midsize, and large cars. Shown are the technology results for analysis of variance of this data table. Assume that a researcher plans to use a 0.05 significance level to test the claim that the different size categories have the same mean chest deceleration in the standard crash test. Complete parts (a) and (b) below. Click the icon to view the table of chest deceleration measurements A Click the icon to view the table of analysis of variance results. ..... a. What characteristic of the data specifically indicates that one-way analysis of variance should be used? O A. There are three samples of measurements. O B. The population means are approximately normal. O C. The measurements are categorized according to the one characteristic of size. O D. Nothing specifically indicates that one-way analysis of variance should be used. b. If the objective is to test…

Two surfers and statistics students collected data on the number of days on which surfers surfed in the last month for 30 longboard (L) users and 30 shortboard (S) users. Treat these data as though they were from two independent random samples. Test the hypothesis that the mean days surfed for all longboarders is larger than the mean days surfed for all shortboarders (because longboards can go out in many different surfing conditions). Use a level of significance of 0.05. Longboard: 4,9,8,4,9,8,8,6,7,9,11,11,11,13,12,16,14,9,11,18,20,15,10,16,20,20,8,20,21,23 O Shortboard: 6,4,4,6,8,8,6,9,4,6,7,5,9,7,4,16,13,11,13,13,11,15,10,10,13,14,11,21,21,12 Determine the hypotheses for this test. Choose the correct answer below. O A. Ho: HL = Hs O B. Ho: HL = Hs OC. Ho: HL # Hs Ha: HL Hs O F. Ho: HL = Ps Ha: HL = Ps Ha: HL = Hs Ha: HL > Hs Find the test statistic for this test. t = (Round to two decimal places as needed.) Find the p-value for this test. p-value = (Round to three decimal places…

Construct a numerical example, i.e., a data set, such that a two-sample t-test will yield an insignificant test result but a pair t-test will yield a significant test result. (For the two-sample t-test, you can either assume equal variances or unequal variances, which will not affect the key idea of this question.) I need to know how this is possible and what the basics of making this data set should be.

Using the ROI data set: For each of the 2 majors test the hypothesis at the 5% significance level: The mean ‘Cost’ for a college is $160,000. Be sure to interpret your results. For Business versus Engineering majors conduct a two sample test of the hypothesis at the 10% significance level (assume the variances are not equal): The average ’30-Year ROI’ for Business majors is less than for Engineering Majors.  Be sure to interpret your results.

The accounting department analyzes the variance of the weekly unit costs reported by two production departments. A sample of 16 cost reports for each of the two departments shows cost variances of 2.3 and 5.4, respectively. Is this sample sufficient to conclude that the two production departments differ in terms of unit cost variance? Use  ? = 0.10. State the null and alternative hypotheses. -H0: ?12 > ?22 Ha: ?12 ≤ ?22 -H0: ?12 ≠ ?22 Ha: ?12 = ?22      -H0: ?12 ≤ ?22 Ha: ?12 > ?22 -H0: ?12 = ?22 Ha: ?12 ≠ ?22 Find the value of the test statistic. (Round your answer to two decimal places.) statistic=?? Find the p-value. (Round your answer to four decimal places. Remember: When using WebAssign technology to find p-values, use the entire test statistic (not the rounded answer from the previous question.)) p-value = ??   State your conclusion. -Reject H0. We can conclude that there is a difference between the population variances. -Do not reject H0. We cannot conclude that…

Qualitative researchers should view the opinions of other researchers about the themes derived from data analysis as biased. This is because other researchers would not be as familiar with the results as the researcher. True False A researcher has conducted a crosstabs analysis to understand the distribution of income across 3 different gender groups (male, female and non-binary). They notes that the Chi-square test produced an asymptotic significance level of 0.027. What does this suggest? (pick the most appropriate interpretation) Income does not vary across different genders Income does not differ across the different grouops There are significant differences in the distribution of income for the male, female and non-binary groups The male group has sufficiently more income compared to the female and non-binary groups

A brokerage firm wants to conduct a study to see if there is a linear relationship between the size of an account and the number of trades conducted each year. What would be the most appropriate procedure to use to analyze data to answer this question? Only choose a test that handles multiple comparisons if such a test is needed. O ANOVA (Analysis of Variance) O Regression Test of Slope or Correlation O Test for a Difference of Proportions O Chi-square test of association O Test for a Difference of Means