
2b. It is thought that 20% of Annual Tax returns to the Australian Tax Office (ATO) contain
errors of one kind or another. An auditor in the ATO investigating the number of returns
with errors in a particular industry takes a sample of 25 returns and classifies each return as
being “in error” or “not in error”.
i. If the variable X is used to represent the number of returns in the sample that are in
error, and assuming this industry is no different to other industries in terms of the error
rate, then state:
• the values that X may take;
• the distribution of this variable; and
• the parameter/s of this distribution.
ii. Determine the
The auditor found that there were 13 tax returns with errors in this sample.
iii. Determine the probability of finding 13 or more returns with errors if indeed the error
rate was 20%.
iv. Based upon your answer for part iii., what conclusion might the auditor make about this
particular industry in terms of the error rate of returns. Say in a full sentence exactly
what led you to this conclusion.

Step by stepSolved in 5 steps with 10 images

- To test for any significant difference in the number of hours between breakdowns for four machines, the following data were obtained. Machine Machine Machine Machine 1 2 3 6.4 9.0 10.8 9.8 8.0 7.8 10.1 12.7 5.3 9.8 9.6 12.0 7.5 10.3 10.1 10.6 8.5 9.4 8.9 11.0 7.5 10.1 8.7 11.1 (a) At the a = 0.05 level of significance, what is the difference, if any, in the population mean times among the four machines? State the null and alternative hypotheses. Ho: H1 = H2 = H3= H4 : Not all the population means are equal. %3D Ho: H1 + H2 # Hz# H4 Hai H1 = H2 = H3 = H4 Hoi H1 = H2 = H3 = H4 Ha: H1 + H2 # H3 %D + H4 Ho: At least two of the population means are equal. Hạ: : At least two of the population means are different. Ho: Not all the population means are equal. Ha: H1 = H2 = H3= H4 Find the value of the test statistic. (Round your answer to two decimal places.) Find the p-value. (Round your answer to three decimal places.) p-valuearrow_forwardToward the middle of the harvesting season, peaches for canning come in three types, early, late, and extra late, depending on the expected date of ripening. During a certain week, the data to the right were recorded at a fruit delivery station. Complete parts (a) through (d) below. 18 trucks (Type a whole number.) (b) How many carried only extra late? (a) How many trucks carried only late variety peaches? 17 trucks (Type a whole number.) (c) How many carried only one type of peach? 40 trucks (Type a whole number.) (d) How many trucks (in all) went out during the 28 trucks went out carrying early peaches; 60 carried late peaches; 46 carried extra late peaches; 19 carried early and late; 25 carried late and extra late; trucks (Type a whole number.) 6 carried early and extra late; 2 carried all three; 5 carried only figs (no peaches at all).arrow_forwardA problem with a phone line that prevents a customer from receiving or making calls is upsetting to both the customer and the telecommunications company. The file “Phone” contains samples of 20 problems reported to two different offices of a telecommunications company and the time toclear these problems (in minutes) from the customers’ lines: Central Office I Time to Clear Problems (minutes) 1.48 1.75 0.78 2.85 0.52 1.60 4.15 3.97 1.48 3.10 1.02 0.53 0.93 1.60 0.80 1.05 6.32 3.93 5.45 0.97 Central Office II Time to Clear Problems (minutes) 7.55 3.75 0.10 1.10 0.60 0.52 3.30 2.10 0.58 4.02 3.75 0.65 1.92 0.60 1.53 4.23 0.08 1.48 1.65 0.72 Assuming that the population variances from both offices are not equal, is there evidence of a difference in the mean waiting time between two offices? (Use a = 0.01) ▪ You may need to download file “Phone”. Referring to Table 10-2, which of the following is an appropriate null hypothesis? Question 2 options: 1)…arrow_forward
- a) by the…regression sum of squares, error sum of squares, or total sum of squares…which for these data is…318.8361, 41.9197, or 362.0680 c) minimizes the…regression sum of squares, error sum of squares, or total sum of squares…which for these data is…318.8361, 41.9197, or 362.0680arrow_forward3. The dataset butterfat in the package faraway contains the average butterfat content (percent- ages) of milk for random samples of twenty cows, ten two-year old and ten mature (greater than four years old), from each of five breeds. Therefore, for each combination of breed and age categories, there are ten observations. The data are from Canadian records of pure-bred dairy cattle. Questions of interest are (i) if butterfat content differs with age and/or breed, and (ii) if any potential breed effect is the same for the two age groups. (a) Make appropriate plots of the data and comment on them. (b) Determine an appropriate model, and write it down mathematically, to answer the questions of interest. What are your conclusions? (c) Is the best breed in terms of butterfat content clearly superior to the second best breed? Justify.arrow_forwardIn which of the following cases is the local average treatment effect not equal to the average treatment effect? A. When an individual's decision to receive treatment depends on the effectiveness of the treatment for that individual. B. When the instrument affects each individual equally. C. When the heterogeneity in the treatment effect and heterogeneity in the effect of the instrument are uncorrelated. D. When the treatment effect is the same for all individuals. Suppose two researchers use two different instruments that are both valid (i.e., both are relevant and exogenous) to estimate the average causal effect in heterogeneous populations. In large samples, the researchers would obtain different TSLS estimates of the average causal effect. different the samearrow_forward
- To test for any significant difference in the number of hours between breakdowns for four machines, the following data were obtained. Machine1 Machine2 Machine3 Machine4 6.7 8.9 11.1 9.9 8.1 7.7 10.3 12.6 5.6 9.6 9.7 11.9 7.6 10.3 10.4 10.8 8.6 9.3 9.1 11.2 7.8 10.0 8.8 11.4 Use the Bonferroni adjustment to test for a significant difference between all pairs of means. Assume that a maximum overall experimentwise error rate of 0.05 is desired. Find the value of LSD. (Round your comparisonwise error rate to three decimal places. Round your answer to two decimal places.) LSD = ??arrow_forwardThe Admission director for a college far from mart and town believes that an inverse relationship exists between a private college's average discount rate(determined by the average amount of scholarships students receive) and the annual yield (the percentage of admitted students who actually attend). The Director's independent variable is a private college's discount rate measured as a percentage, and the dependent variable is the college's annual yield measured as a percentage. The following results were obtained for a sample of 30 private colleges: x- Discount rate(percentage) - range: 35 to 72 percent y- Annual Yield(percentage) - range: 12 o 81 percent Σxi = 1612 Σyi = 898 Σxiyi = 44,377 Σxi2 = 89,790 Σyi2 = 35,704 a. Calculate the sample regression line's slope estimate. Interpret the sample regression line's slope estimate. b. Calculate the sample regression line's intercept estimate. Interpret the sample regression line's intercept estimate. Assume the following sum of…arrow_forward3. Travelers who have no intention of showing up often fail to cancel their hotel reservations in a timely manner. These travelers are known, in the parlance of the hospitality trade, as "no-shows". To protect against no-shows and late cancellations, hotels invariably overbook rooms. A recent study examined the problems of over-booking rooms in the hotel industry. The following data, extracted from the study represent the daily numbers of late cancellations and no-shows for a random sample of 10 days at a hotel: 18, 16, 16, 16, 14, 18, 16, 18, 14, 19. e) Suppose the relative frequency distribution for the data is bell-shaped, then what percentage of observations are more than 18.2? (Hint: use Empirical rule) 2.5% 32% 16% 5%arrow_forward
- To test for any significant difference in the number of hours between breakdowns for four machines, the following data were obtained. Machine1 Machine2 Machine3 Machine4 6.6 9.1 10.9 9.6 8.1 7.8 9.9 12.4 5.6 9.7 9.4 11.7 7.8 10.3 10.1 10.6 8.8 9.5 8.8 10.9 7.5 10.0 8.5 11.4 (a) At the ? = 0.05 level of significance, what is the difference, if any, in the population mean times among the four machines? State the null and alternative hypotheses. H0: ?1 ≠ ?2 ≠ ?3 ≠ ?4Ha: ?1 = ?2 = ?3 = ?4 H0: ?1 = ?2 = ?3 = ?4Ha: ?1 ≠ ?2 ≠ ?3 ≠ ?4 H0: At least two of the population means are equal.Ha: At least two of the population means are different. H0: Not all the population means are equal.Ha: ?1 = ?2 = ?3 = ?4 H0: ?1 = ?2 = ?3 = ?4Ha: Not all the population means are equal. Find the value of the test statistic. (Round your answer to two decimal places.) Find the p-value. (Round your answer to three decimal places.) p-value = State your conclusion. Reject…arrow_forwardConsider two data sets. Set A: n = 5; x = 4 Set B: n = 50; x = 4 (a) Suppose the number 26 is included as an additional data value in Set A. Compute x for the new data set. Hint: x = nx. To compute x for the new data set, add 26 to x of the original data set and divide by 6. (Round your answer to two decimal places.) (b) Suppose the number 26 is included as an additional data value in Set B. Compute x for the new data set. (Round your answer to two decimal places.)arrow_forwardWhich of the following claims would result in a Left tail test? O A. Claim: The average heart rate for exercisers is lower than the average heart rate for nonexercisers. B. Claim The variation in the grades of the Final Exam are different than previously (which was 2.3). O C. Claim: The proportion of people with pets is over 75%. OD. Claim: The average age of voters in Clarke County is not 45 years.arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman





