Wheat Box Breakfast Company is developing new flavors of breakfast cereal. They want to see what people think of Croonchy Crisp, their newest cereal. They create 3 different Croonchy Crisp recipes and serve it to 3 different groups. Each group eats 2 bowls of Croonchy Crisp and grades it on taste, smell, and (of course) croonchiness. Is this an observational or experimental study?

Wheat Box Breakfast Company is developing new flavors of breakfast cereal. They want to see what people think of Croonchy Crisp, their newest cereal. They create 3 different Croonchy Crisp recipes and serve it to 3 different groups. Each group eats 2 bowls of Croonchy Crisp and grades it on taste, smell, and (of course) croonchiness. Is this an observational or experimental study?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

Do people feel hungrier after sampling a healthy food? The authors of a consumer research paper carried out a study to answer this question. They randomly assigned volunteers into one of three groups. The people in the first group were asked to taste a snack that was described as a new health bar containing high levels of protein, vitamins, and fiber. The people in the second group were asked to taste the same snack but were told it was a tasty chocolate bar with a raspberry center. After tasting the snack, participants were asked to rate their hunger level on a scale from 1 (not at all hungry) to 7 (very hungry). The people in the third group were asked to rate their hunger but were not given a snack. The data in the table are consistent with summary quantities given in the paper (although the sample sizes in the actual study were larger). TreatmentGroup Hunger Rating SampleMean SampleStandardDeviation Healthy 5 8 7 4 7 3 4 7 6 5.6667 1.7321 Tasty 4 1 5 2 6 2 5 3 4 3.5556…
A randomly sampled group of patients at a major U.S. regional hospital became part of a nutrition study on dietary habits. Part of the study consisted of a 50-question survey asking about types of foods consumed. Each question was scored on a scale from one (most unhealthy behavior) to five (most healthy behavior). The answers were summed and averaged. The population of interest is the patients at the regional hospital. The current survey was implemented after patients were subjected to this education, and it produced the following sample statistics for 25 patients sampled: and s = 1.02. We would like to know if the education improved nutrition behavior. We test the hypotheses H 0: = 2.9 versus Ha: > 2.9. The value of the t test is 1.96, and: a. P-value > 0.1. b. 0.025 P-value < 0.05. c. 0.25 P-value < 0.01. d. 0.05 P-value < 0.1. Given the least squares regression line y = 3 x – 3, which of the following is true? a. The…
StarHortons Cup, the coffee company, wants to determine how long caffeine lasts throughout the day when individuals have a cup of one of their 3 types of coffee at 9am. They will then measure the levels of caffeine in these individuals’ systems at 10am, 12am, 2pm, 4pm, 6pm and 8pm. They want to have at least 20 observations per group. How many separate/distinct groups of participants are needed if they want to conduct this experiment using a mixed-measures ANOVA? 18 6 20 3
A gym wishes to evaluate the effectiveness of its programs. When a new member joins the gym, they meet with a trainer who designs a recommended routine based on the member’s current fitness and their goals. The recommended routines can be classified into high, medium, or low effort. Historically, 68% of the new members get a high effort routine, 21% get a medium effort routine, and the rest get a low effort routine. After the first six months as members, the gym surveys the members’ adherence to the recommended routine. The gym classifies a member’s performance as optimal if they follow the recommended routine for the six months, or as inferior otherwise. According to the historical results of the survey, 84% of the members with a low effort routine, 22% of the members with a medium effort routine, and 69% of the members with a high effort routine report optimal performance. After the first six months of joining the gym, a member can obtain different results: they can either…
This semester, we have talked about creating random samples as well as desirable qualities of random samples. Other than randomness, one quality of random samples that we have talked about is representation. Using your knowledge of that concept, consider this problem. At a college, 29% of the students are in their first year, 27% are in their second year, 25% in their third, and 19% in their fourth. You take a survey of students and when you classify them by year of study, you have 49, 70, 56, and 25 students in their first, second, third, and fourth years respectively. The table below highlights this information. Year of School First Second Third Fourth Total College Percents Sample Counts Expected Counts 27% 70 25% 56 29% 19% 49 25 200 58 54 50 38 Under the assumption that we think the college enrollment percentages should match our sample, and that therefore our sample represents the college: a) What would the critical value be? (use a = 0.05) b) Find the test statistic to test (c)…
Ecologists conducted a study to investigate the potential ecological impact of golf courses. Investigators monitored the reproductive success of bluebirds in birdhouses at nine golf courses and ten similar birdhouses at nongolf sites. Data on nests in birdhouses occupied only by bluebirds are shown in the table. If the proportions of nests occupied is the same for golf and nongolf sites, what would be the expected count of birdhouse with 1 nest in nongolf locations? O nests 1 nest Total 2 or 3 nests Golf 30 42 8 80 Nongolf 40 58 22 120 Total 70 100 30 200 50 b 42 60 d. 58 e 40 O O O O O
You are a sales manager for a grocery store, and you want to see if the introduction of a new sales promotion will increase the sales in your store. To do so, you decided to create an experiment by giving a small sample of customers the promotion before expanding it to a larger customer base. You gave 18 people the promotion, and also observed the sales of 27 people who did not get the promotion as a control group. You found those who received the promotion to have an average monthly sales of $456.60, with a sample standard deviation of $52.23. You found those who did not receive the promotion had an average monthly sales of $361.46, with a sample standard deviation of $56.11. Suppose you want to use hypothesis testing (two-sample test) to investigate if the promotion has increased the sales of your store. Using the order promotion no promotion in your hypothesis test, what is the value of the test statistic for your analysis? Note: 1- Only round your final answer. Round your final…
Suppose you were presented with the results of a study comparing two different training methods for basketball athletes. You are told 32 athletes were randomly assigned to the two groups so that 16 were in the group A and 16 were in the group B. At the end of the session, the average scores (wins versus losses) of the two groups/teams were compared and a difference of 10% was observed ( the first team had 10% more wins than the second). The coach observer reports two- sample t-test shows this difference is statistically significant. How would you interpret these findings? What questions or concerns would you have? How might this type of study be improved? Hint: Consider the possibility that the test performed was not the appropriate one.
Psychologists at Disney World measured factors that affect the scariness of the soundtrack for their Haunted House ride. In particular, they were interested in the loudness of the screams (soft versus loud) and the length of the screams (short versus long). They used a 2 × 2 factorial design to test how these factors combined. They collected data from 10 different riders in each of the four conditions. Each rider rated the scariness of the ride on a nine-point scale. short screams long screams soft screams T=38, n = 10, SS = 13.6 T=64, n = 10, SS = 22.4 loud screams T=52, n=10, SS = 29.6 T=50, n=10, SS = 16.0 For these data: G = 204, N = 40, X2 = 1156. 1. Sketch a dataplot of the mean rating in each condition. 2. Calculate SS total, the total sum of squares 3. Calculate SSwithin, the within-treatments sum of squares. 4. Calculate SSbetween, the between-treatments sum of squares. 5. Calculate SSA the sum of squares for Factor A (length of scream). 6. Calculate SSB, the sum of squares…
To determine the amount of sugar in a typical serving of breakfast cereal, a student randomly selected 60 boxes of different types of cereal from the shelves of a large grocery store. The student noticed that the side panels of some of the cereal boxes showed sugar content based on one-cup servings, while others showed sugar content based on three- quarter-cup servings. Many of the cereal boxes with side panels that showed three-quarter-cup servings were ones that appealed to young children, and the student wondered whether there might be some difference in the sugar content of the cereals that showed different-size servings on their side panels. To investigate the question, the data were separated into two groups. One group consisted of 29 cereals that showed one-cup serving sizes; the other group consisted of 31 cereals that showed three-quarter cup serving sizes. The boxplots shown below display sugar content (in grams) per serving of the cereals for each of the two serving sizes.…
A biologist is studying the plant diversity in 15 million acres of the Sierra Nevada Mountains. He will count the number of species in 150 acres. Match the strategies to their corresponding sampling techniques. The biologist goes to his 150 favorite hiking places and looks at an acres along each trail. v The biologist enters the 15 million acres into a data base and had a computer randomly select 150 of these acres. The biologist classifies the Sierras into 10 different ecological types and then makes sure that the proportion of each ecological type from the sample is the same as the proportion of that of the population. The biologist orders the 15 million acres by latitude and then surveys every 100000th acre on the list. | The biologist goes to 15 diverse locations that have 10 acres each and surveys all 10 acres for each of these 15 locations. a. Convenience Sampling b. Cluster Sampling c. Systematic Sampling d. Stratified Sampling e. Simple Random Sampling
A doctor wanted to study the effect of four different treatments on mental health. A group of 100 adults experiencing depression volunteered for the study. The doctor randomly assigned one-fourth of them to each of four groups. Group 1 followed a specific exercise plan, group 2 followed a specific diet plan, group 3 followed an exercise and diet plan, and group 4 did not follow any plan. After 4 weeks, the doctor contacted each participant and asked them if they felt any better. The results are displayed in the table. The doctor would like to know if these data provide convincing evidence that the distribution of responses differs across the treatment groups in the population of all patients like these. The random condition is met. The 10% condition is not needed because random sampling did not take place. This table of expected counts shows that all expected counts are at least 5. What is the value of the chi-square test statistic? χ‑2 = 5.03 χ‑2 = 6.26 χ‑2 = 25.33 χ‑2 = 39.22