Concept explainers
Naughty or Nice? An experiment was conducted in which 16 ten-month-old babies were asked to watch a climber character attempt to ascend a hill. On two occasions, the baby witnesses the character fail to make the climb. On the third attempt, the baby witnesses either a helper toy push the character up the hill, or a hinderer toy preventing the character from making the ascent. The helper and hinderer toys were shown to each baby in a random fashion for a fixed amount of time. In Problem 39 from Section 10.2, we learned that, after watching both the helper and hinderer toy in action, 14 of 16 ten-month-old babies preferred to play with the helper toy when given a choice as to which toy to play with. A second part of this experiment showed the climber approach the helper toy, which is not a surprising action, and then alternatively the climber approached the hinderer toy, which is a surprising action. The amount of time the ten-month-old watched the
Source: J. Kiley Hamlin et al., “Social Evaluation by Preverbal Infants,” Nature, Nov. 2007.
- a. State the null and alternative hypothesis to determine if babies tend to look at the hinderer toy longer than the helper toy.
- b. Assuming the differences are
normally distributed with no outliers, test if the difference in the amount of time the baby will watch the hinderer toy versus the helper toy is greater than 0 at the 0.05 level of significance. - c. What do you think the results of this experiment imply about 10-month-olds’ ability to assess surprising behavior?
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Fundamentals of Statistics (5th Edition)
- One game at a carnival is called “Duck Pond.” This game consists of a large number of ducks that arefloating through an oval-shaped trough. A sign claims that 20% of the ducks have a blue dot on thebottom of them, 20% have a red dot, 20% have a green dot, 20% have a yellow dot, and 20% have anorange dot. Players pay to select one duck, show the color to the game attendant, replace the duck, spinaround once, and then select a second duck. If the dot on the bottom of the second duck matches the dotthat was on the bottom of the first duck, the player wins. Otherwise, the player loses. a) Are the events “color of the first duck” and “color of the second duck” independent? Explain. b) You want to perform a simulation to estimate the probability of winning this game, assuming theduck colors are distributed as claimed. Describe how you could use a table of random digits tocarry out this simulation without needing to skip any digits. c) Perform 10 trials of the simulation described in part (b)…arrow_forwardMany animals, including humans, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot patterns on their wings to help ward off predators. Scaife (1976) reports a study examining how eye-spot patterns affect the behavior of birds. In the study, the birds were tested in a box with two chambers and were free to move from one chamber to another. In one chamber, two large eye-spots were painted on one wall. The other chamber had plain walls. The researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M=34.5 minutes on the plain chamber with SS=210 for a sample of n=15 birds. (Note: If the eye spots have no effect, then the birds should spend an average of ?=30minutes in each chamber.) a. Is this sample sufficient to conclude that the eye-spots have a significant influence on the birds' behavior? Use a two-tailed test with ?=.05. b.…arrow_forwardMany animals, including humans, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot patterns on their wings to help ward off predators. Scaife (1976) reports a study examining how eye-spot patterns affect the behavior of birds. In the study, the birds were tested in a box with two chambers and were free to move from one chamber to another. In one chamber, two large eye-spots were painted on one wall. The other chamber had plain walls. The researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M = 37 minutes in the plain chamber with SS = 288 for a sample of n = 9 birds. (Note: If the eye-spots have no effect, then the birds should spend an average of μ = 30 minutes in each chamber.) Is this sample sufficient to conclude that the eyespots have a significant influence on the birds’ behavior? Use a two-tailed test with α = .05.…arrow_forward
- Many animals, including humans, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot patterns on their wings to help ward off predators. Scaife (1976) reports a study examining how eye-spot patterns affect the behavior of birds. In the study, the birds were tested in a box with two chambers and were free to move from one chamber to another. In one chamber, two large eye-spots were painted on one wall. The other chamber had plain walls. The researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M=37minutes in the plain chamber with SS=288 for a sample of n=9 birds. (Note: If the eye-spots have no effect, then the birds should spend an average of μ=30 minutes in each chamber.) Is this sample sufficient to conclude that the eye-spots have a significant influence on the birds’ behavior? Use a two-tailed test with a= .05. Compute the…arrow_forwardMany animals, including humans, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot patterns on their wings to help ward off predators. Scaife (1976) reports a study examining how eye-spot patterns affect the behavior of birds. In the study, the birds were tested in a box with two chambers and were free to move from one chamber to another. In one chamber, two large eye-spots were painted on one wall. The other chamber had plain walls. The researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M = 34.5 minutes on the plain chamber with SS = 210 for a sample of n = 15 birds. (Note: If the eye spots have no effect, then the birds should spend an average of μ = 30 minutes in each chamber.) a. Is this sample sufficient to conclude that the eyespots have a significant influence on the birds’ behavior? Use a two-tailed test with α =…arrow_forwardAn experiment investigated the effect of length and repetition of TV ads on students choosing to eat at Del Taco. All 60 students watched a 40-minute television program that included ads for Del Taco. Some students saw a 30-second commerical; others a 90-second commerical. The same commerical was shown either 1, 3, or 5 times during the program. After the viewing, each student was asked to rate their craving for Del Taco on a scale of 0 to 10. What is the response variable?A. 1, 3, or 5 commercials during the 40-minute television programB. craving for Del Taco on a scale of 0 to 10C. 60 studentsD. 30-second and 90-second commericialsE. 40-minute television programarrow_forward
- An experiment investigated the effect of length and repetition of TV ads on students choosing to eat at Del Taco. All 60 students watched a 40-minute television program that included ads for Del Taco. Some students saw a 30-second commerical; others a 90-second commerical. The same commerical was shown either 1, 3, or 5 times during the program. After the viewing, each student was asked to rate their craving for Del Taco on a scale of 0 to 10. What are the subjects of this experiment?A. 60 studentsB. effect of length and repetion of TV adsC. 40-minute television programD. craving for Del Taco on a scale of 0 to 10E. 1, 3, or 5 commercials during the 40-minute television programarrow_forwardAn experiment investigated the effect of length and repetition of TV ads on students choosing to eat at Del Taco. All 60 students watched a 40-minute television program that included ads for Del Taco. Some students saw a 30-second commerical; others a 90-second commerical. The same commerical was shown either 1, 3, or 5 times during the program. After the viewing, each student was asked to rate their craving for Del Taco on a scale of 0 to 10. What are the factors? O A. 40-minute television program O B. length and repetition of TV ads OC. craving for Del Taco on a scale of 0 to 10 OD. 1, 3, or 5 commercials during the 40-minute television program O E. 60 studentsarrow_forwardCan an interviewer influence how people respond to the survey question, "Do you like dogs?" To answer this question, Jason carried out an experiment. As each person approached, Jason flipped a coin. If it landed on heads, Jason picked up his puppy and asked the person if they like dogs. If the coin landed on tails, Jason picked up a clipboard and asked the person if they like dogs. Of the 50 people that Jason surveyed while holding his puppy, 35 said "Yes," while 11 of the 44 people that Jason surveyed while holding his clipboard said "Yes." Let p₁ = the true proportion of people like the ones in this study who would say they like dogs when Jason is holding his puppy and p2 = the true proportion of people like the ones in this study who would say they like dogs when Jason is holding a clipboard. Construct and interpret a 90% confidence interval for the difference in the proportion of people like these who would say they like dogs when Jason is holding his puppy or a clipboard. O…arrow_forward
- You survey college bound and find that 85% plan to liv eon campus, 35% plan to have a car while at campus and 5% plan to live off campus and not have a car. Is there an association between living on campus and having a car at college?arrow_forwardA study conducted at Manatee Community College revealed that students who attended class 95 to 100% of the time usually received an A in the class. Students who attended class 80 to 90% of the time usually received a B or C in the class. Students who attended class less than 80% of the time usually received a D or an F or eventually withdrew from the class. Based on this information, attendance and grades are related. The more you attend class, the more likely you will receive a higher grade. If you improve your attendance, your grades will probably improve. Many factors affect your grade in a course. One factor that you have considerable control over is attendance. You can increase your opportunities for learning by attending class more often. 1. What are the variables under study? 2. What are the data in the study? 3. Are descriptive, inferential, or both types of statistics used? 4. What is the population under study? 5. Was a sample collected? If so, from where? 6.…arrow_forwardA psychologist wanta to determine the effect of relaxing music on a person's reaction to a stressful event. Participants were randomly assigned to one of three groups. A participant was brought into a room with no windows and only one door. In the background, either soft classical music, or no music at all was playing. After a set amount of time, a fire alarm went off, and smoke started to come from under the door. A hidden video camera records the participants behavior that is later scored by the experimenter for level of panic from 0-100. Which statistical test would be best to determine if there is a significant difference between groups? One sample t test Dependent samples t test Independent t test ANOVAarrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage