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Do you consider yourself a chocoholic? There are times when you suddenly have an uncontrolla urge for chocolates – candy bars, brownies, doughnuts, ice cream, or drink. A bar of choco contains hundreds of chemicals such as stimulants that contribute to a temporary sense wellbeing. Until now, several researchers are still studying the effects of chocolate on the brair Chocolates consist of particles of cocoa powder and sugar. Cocoa is a rich source of flavanols that have b found to benefit human cognitive function, particularly attention and memory. A random sample of 90 stude at a certain university was selected to participate in a study that will investigate whether consuming chocola with higher flavanol content improves cognition, particularly reaction time. The students were randomly assig to one of two groups. The 45 students in the first group were asked to consume 35g of dark chocolate bar (I flavanol content) while the remaining 45 students in the second group were asked to consume 35g of w chocolate bar (low flavanol content).

Do you consider yourself a chocoholic? There are times when you suddenly have an uncontrolla urge for chocolates – candy bars, brownies, doughnuts, ice cream, or drink. A bar of choco contains hundreds of chemicals such as stimulants that contribute to a temporary sense wellbeing. Until now, several researchers are still studying the effects of chocolate on the brair Chocolates consist of particles of cocoa powder and sugar. Cocoa is a rich source of flavanols that have b found to benefit human cognitive function, particularly attention and memory. A random sample of 90 stude at a certain university was selected to participate in a study that will investigate whether consuming chocola with higher flavanol content improves cognition, particularly reaction time. The students were randomly assig to one of two groups. The 45 students in the first group were asked to consume 35g of dark chocolate bar (I flavanol content) while the remaining 45 students in the second group were asked to consume 35g of w chocolate bar (low flavanol content).

MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
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PROBLEM 2: Trick or treat from flavanols! Do you consider yourself a chocoholic? There are times when you suddenly have an uncontrollable urge for chocolates – candy bars, brownies, doughnuts, ice cream, or drink. A bar of chocolate contains hundreds of chemicals such as stimulants that contribute to a temporary sense of wellbeing. Until now, several researchers are still studying the effects of chocolate on the brain. Chocolates consist of particles of cocoa powder and sugar. Cocoa is a rich source of flavanols that have been found to benefit human cognitive function, particularly attention and memory. A random sample of 90 students at a certain university was selected to participate in a study that will investigate whether consuming chocolates with higher flavanol content improves cognition, particularly reaction time. The students were randomly assigned to one of two groups. The 45 students in the first group were asked to consume 35g of dark chocolate bar (high flavanol content) while the remaining 45 students in the second group were asked to consume 35g of white chocolate bar (low flavanol content). For two hours prior to the study, the students were asked to fast from all food and drink except water. On arrival, the students answered a questionnaire to report some demographic information. The students then consumed the assigned chocolate bar and stayed in the classroom while still fasting. After 30 minutes, the students were given a cognitive task. They were instructed to press one of the buttons on the computer keyboard as quickly as possible in response to the letters, numbers, or symbols that appeared on the screen. The next character would be displayed on the screen as soon the correct button is pressed. A total of 60 characters appeared on the screen. The total reaction time (in seconds) of each student was recorded. Consider d = Xdark – Xwhite Where Xdark is the total reaction time of a student who consumed dark chocolate and Xwhite is the total reaction time of a student who consumed white chocolate. R COMMANDER OUTPUT #2.1 R COMMANDER OUTPUT #2.3 Shapiro-Wilk normality test reaction.time data: chocolate = dark W = 0.98837, p-value = 0.927 chocolate white W = 0.97259, p-value = 0. 3581 R COMMANDER OUTPUT #2.2 F test to compare two variances reaction.time by chocolate data: F = 1.3668, num df = 44, denom df = 44, p-value = 0.3037 alternative hypothesis: true ratio of variances is not equal to 1 dark white chocolate R COMMANDER OUTPUT #2.4 Parametric test data: reaction.time by chocolate t = 1.1107, df = 88, p-value = 0.2697 alternative hypothesis: true difference in means is not equal to 0 t = 1.1107, df = 88, p-value = 0.1349 alternative hypothesis: true difference in means is greater than 0 t = 1.1107, df = 88, p-value = 0.8651 alternative hypothesis: true difference in means is less than 0 R COMMANDER OUTPUT #2.5 Nonparametric test data: reaction.time by chocolate W = 1170.5, p-value = 0.2027 alternative hypothesis: true location shift is not equal to 0 W = 1170.5, p-value = 0.1014 alternative hypothesis: true location shift is greater than 0 W = 1170.5, p-value alternative hypothesis: true location shift is less than 0 0.9001 %3D reaction time 12.0 125 13.0 13.5 14.0 14.5
Transcribed Image Text:PROBLEM 2: Trick or treat from flavanols! Do you consider yourself a chocoholic? There are times when you suddenly have an uncontrollable urge for chocolates – candy bars, brownies, doughnuts, ice cream, or drink. A bar of chocolate contains hundreds of chemicals such as stimulants that contribute to a temporary sense of wellbeing. Until now, several researchers are still studying the effects of chocolate on the brain. Chocolates consist of particles of cocoa powder and sugar. Cocoa is a rich source of flavanols that have been found to benefit human cognitive function, particularly attention and memory. A random sample of 90 students at a certain university was selected to participate in a study that will investigate whether consuming chocolates with higher flavanol content improves cognition, particularly reaction time. The students were randomly assigned to one of two groups. The 45 students in the first group were asked to consume 35g of dark chocolate bar (high flavanol content) while the remaining 45 students in the second group were asked to consume 35g of white chocolate bar (low flavanol content). For two hours prior to the study, the students were asked to fast from all food and drink except water. On arrival, the students answered a questionnaire to report some demographic information. The students then consumed the assigned chocolate bar and stayed in the classroom while still fasting. After 30 minutes, the students were given a cognitive task. They were instructed to press one of the buttons on the computer keyboard as quickly as possible in response to the letters, numbers, or symbols that appeared on the screen. The next character would be displayed on the screen as soon the correct button is pressed. A total of 60 characters appeared on the screen. The total reaction time (in seconds) of each student was recorded. Consider d = Xdark – Xwhite Where Xdark is the total reaction time of a student who consumed dark chocolate and Xwhite is the total reaction time of a student who consumed white chocolate. R COMMANDER OUTPUT #2.1 R COMMANDER OUTPUT #2.3 Shapiro-Wilk normality test reaction.time data: chocolate = dark W = 0.98837, p-value = 0.927 chocolate white W = 0.97259, p-value = 0. 3581 R COMMANDER OUTPUT #2.2 F test to compare two variances reaction.time by chocolate data: F = 1.3668, num df = 44, denom df = 44, p-value = 0.3037 alternative hypothesis: true ratio of variances is not equal to 1 dark white chocolate R COMMANDER OUTPUT #2.4 Parametric test data: reaction.time by chocolate t = 1.1107, df = 88, p-value = 0.2697 alternative hypothesis: true difference in means is not equal to 0 t = 1.1107, df = 88, p-value = 0.1349 alternative hypothesis: true difference in means is greater than 0 t = 1.1107, df = 88, p-value = 0.8651 alternative hypothesis: true difference in means is less than 0 R COMMANDER OUTPUT #2.5 Nonparametric test data: reaction.time by chocolate W = 1170.5, p-value = 0.2027 alternative hypothesis: true location shift is not equal to 0 W = 1170.5, p-value = 0.1014 alternative hypothesis: true location shift is greater than 0 W = 1170.5, p-value alternative hypothesis: true location shift is less than 0 0.9001 %3D reaction time 12.0 125 13.0 13.5 14.0 14.5
PROBLEM 2: Trick or treat from flavanols! The researcher in this study wishes to investigate whether consuming chocolates with higher flavanol content improves cognition, particularly reaction time. The variable of interest is the to enter text. which is in the illustrates the use of level of measurement. The random sample of students samples. The p-values obtained from the Shapiro-Wilk test indicate that the assumption of was . Further, results obtained from the F-test indicate that the assumption of . Considering the variable of interest, the type of samples, ana tne results of the test for the assumptions, the appropriate test procedure to analyze the given data is the was Based on the p-value equal to evidence to say that it can be said that we have no sufficient
Transcribed Image Text:PROBLEM 2: Trick or treat from flavanols! The researcher in this study wishes to investigate whether consuming chocolates with higher flavanol content improves cognition, particularly reaction time. The variable of interest is the to enter text. which is in the illustrates the use of level of measurement. The random sample of students samples. The p-values obtained from the Shapiro-Wilk test indicate that the assumption of was . Further, results obtained from the F-test indicate that the assumption of . Considering the variable of interest, the type of samples, ana tne results of the test for the assumptions, the appropriate test procedure to analyze the given data is the was Based on the p-value equal to evidence to say that it can be said that we have no sufficient
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