The article "Well-Fed Crickets Bowl Maidens Overt reported that female field crickets are attracted to males that have high chirp rates and hypothesized that chirp rate is related to nutritional status. The chirp rates for male field crickets were reported to vary mean of 60 chirps per second. To investigate whether chirp rate is related to nutritional status, investigators fed male crickets a high-protein diet for 8 days and then measured chirp rate. The mean chirp rate for the crickets on the high-protein diet was report 103 chirps per second. Is this convincing evidence that the mean chirp rate for crickets on a high-protein diet is greater than 60 (which would then imply an advantage in attracting the ladies)? Suppose that the sample size and sample standard deviation are n = 40. You can test the relevant hypotheses to answer this question. A significance level of a = 0.01 will be used. A USE SALT (a) State the null and alternative hypotheses. O Ho: H- 60 H:H 60 O Hạ: = 60 H < 60 O Hạ: H< 60 H:> 60 O Hạ: = 60 H: > 60 (b) Calculate the test statistic. (Round your answer to two decimal places.) %3D (c) Based on a = 0.01, what is the correct conclusion for the hypothesis test? (Use a table or SALT.) O we would reject the null hypothesis. This means on the basis of the evidence, you can conclude that the mean chirp rate for male field crickets that eat a high-protein diet is greater than 60.

Suppose that the average waiting time for a patient at a physician's office is just over 29 minutes. In order to address the issue of long patient wait times, some physicians' offices are using wait-tracking systems to notify patients of expected wait times. Patients can adjust their arrival times based on this information and spend less time in waiting rooms. The following data show wait times (minutes) for a sample of patients at offices that do not have a wait-tracking system and wait times for a sample of patients at offices with a wait-tracking system. Without Wait- Tracking System 25 65 16 22 35 46 12 27 12 32 Z-score = With Wait-Tracking System 33 9 15 18 10 32 9 (a) Considering only offices without a wait-tracking system, what is the z-score for the 10th patient in the sample (wait time = 32 minutes)? If required, round your intermediate calculations and final answer to two decimal places. 3 12 17 Z-score = (b) Considering only offices with a wait-tracking system, what is the…

Data are collected in an experiment designed to in- vestigate the impact of different positions of the mother during ultrasound on fetal heart rate. Fetal heart rate is measured by ultrasound in beats per minute. The study includes 20 women who are as- signed to one position and have the fetal heart rate measured in that position. Each woman is between 28 weeks and 32 weeks gestation. The data are shown in Table 7–7. Is there a significant difference in mean fetal heart rates by position? Run the test at a 5% level of significance. back        side      sitting        standing 140          141         144            147 144          143        145            145 146          145         147           148 141           144        148            149 139          136        144            145

Many small restaurants in Portland, Oregon, and other cities across the United States do not take reservations. Owners say that with smaller capacity, no-shows are costly, and they would rather have their staff focused on customer service rather than maintaining a reservation system. However, it is important to be able to give reasonable estimates of waiting time when customers arrive and put their name on the waiting list. The file RestaurantLine contains 10 observations of number of people in line ahead of a customer (independent variable x) and actual waiting time (dependent variable y). The estimated regression equation is: ŷ=4.35+8.81x and MSE=94.4236. Point Estimate for customers who arrive with 3 people on the wait list is 30.8 minutes. a. Develop a 95% confidence interval for the mean waiting time for a customer who arrives with three customers already in line (to 2 decimals). b. Develop a 95% prediction interval for Roger and Sherry Davy's waiting time if there are three…

A veterinarian wants to perform a study at a local animal shelter where 200 dogs need training on behavior modification. The purpose of the study would be to determine if using a firm voice during training for 10 minutes improves a dog's learning behavior compared to not speaking during training for 10 minutes. Part A: Describe an appropriate design for the study. Part B: The hypotheses for this study are as follows: Ho: There is no difference in the mean improvement of dogs during behavior modification for either treatment. Ha: The mean improvement of dogs during behavior modification is greater for the firm voice treatment. The shelters will allow trainers to use a firm voice during training if the null hypothesis is rejected. What are the possible Type I and II errors? Describe the consequences of each in the context of this study and discuss which type you think is more serious.n

A longitudinal study was conducted to investigate if a 3 week "Green" program can change people's attitude's towards recycling. Participants were randomly allocated into two groups: (1) those who received the Green program and (2) those who did not receive the Green program. Each participant completed a survey (measured on a metric scale) which measured their attitudes towards recycling at the end of each week of the study. It was hypothesised that those in the Green program would have more positive attitudes towards recycling compared to those in the non Green group. It was also hypothesised that this difference would be largest at the end of week 3 of the study.  Which of the following would be an appropriate statistical test to conduct, which addresses these hypotheses? Group of answer choices: Within subjects ANOVA Mixed ANOVA Single factor ANOVA Factorial ANOVA Multiple Regression

An occupational safety officer for a large company is conducting a study to investigate back problems in office workers who use a computer for most of the workday. The study will investigate the difference in back problems for workers who stand and workers who sit. A group of 68 volunteers have agreed to participate in the nine-month study. Half the group is randomly assigned to work while standing, and the other half is assigned to work while sitting. At the end of the study, the mean number of back problems between the two groups will be calculated. The officer will use the results to estimate the difference in the mean number of back problems between those who work while standing and those who work while sitting. Which of the following is an appropriate inference procedure for the study? A A one-sample t-interval for a population mean A one-sample t-interval for a sample mean A matched pairs t-interval for a mean difference D A two-sample t-interval for a difference between sample…

A purchasing manager for a large university is investigating which brand of LCD projector to purchase to equip their classrooms. Of major concern is the longevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, and wishes to determine if there is any difference between the two brands in the mean lifetime of the bulbs used. The purchasing manager obtained thirteen projectors of each brand for testing over the last several academic terms. The number of hours the bulbs lasted on each of the thirteen projectors is given in the table. Lifetimes of light bulbs (hours) Infocus 830, 867, 1013, 986, 819, 809, 691, 903, 673, 909, 957, 820, 715 Proxima 532, 718, 769, 806, 779, 970, 903, 1043, 947, 792, 841, 752, 689 Send data to calc... v Send data to Excel Assume that the two populations of lifetimes, are normally distributed and that the population variances are equal. Can we conclude, at the 0.01…

When you get a surprisingly low price on a product do you assume that you got a really good deal or that you bought a low-quality product?  Research indicates that you are more likely to associate low price and low quality if someone else makes the purchase rather than yourself.  In a similar study, 16 participants were asked to rate the quality of low-priced items under two scenarios:  purchased by a friend or purchased yourself.  The results produced a mean difference of 2.6 and a SS = 135, with self-purchases rated higher.  Is there evidence that the judged quality of objects significantly increase for self-purchases than for purchases made by others?  Please use a one-tailed test with level of significance of 5%.

Is narcissism a more common personality trait today than it was a few decades ago?  It is known that the mean population score on the Narcissistic Personality Inventory (NPI) for students attending University of South Alabama around 20 years ago was μ= 15 (Twenge, 2010).  Interested in the narcissism levels of students in the year 2020, a researcher administers the NPI to a random sample of 25 University of Alabama sophomores this Spring term. The mean NPI score from the researcher’s sample of sophomores is M = 16.5, with s = 3.4. 1. Write the null and alternative hypotheses in symbols. Possible symbols for your answer: H0, H1, μ, M, σ. 2. Calculate the standard error.  3. Find the critical value for the test statistic, assuming alpha = .05 (Use largest [i.e., most conservative] value if exact value not given in the chart)  a) 2.064 b) 1.96 c) 1.98 d) 2.000