3. [25 marks] Some female psychology students were investigating whether intelligence depends on brain size. They each took a standard test that measured verbal IQ and also underwent an MRI scan to measure their brain size.
The variables are:
IQ Result of the verbal IQ test. IQ is measured on an artificial index scale, usually meant to have an average value of 100.
BrainV Brain volume measured in thousands of ‘pixels’. The size of a pixel derives from the two-dimensional resolution of the MRI and the spacing of image ‘slices’. It can vary between scanners (and even between scans on the same scanner). The pixel size is the same for all scans in this study, but the standard volumetric equivalent (e.g., millilitres) is not known.
(e) Provide a 95% prediction interval for the verbal IQ of a female whose brain volume was 870,000 pixels. [4]
(f) One of the students showed the scatterplot to a friend who said, “Well, there is clearly a trend there. It looks like people with larger brains do have higher IQ.” Write a brief response to this comment. [2]
e)
Note that IQ is dependent variable
and Brain Volume is independent variable
data <- read.csv("../Documents/brainIq.csv")
BrainV <- data[,2]
IQ <- data[,1]
model <- lm(IQ ~ BrainV)
summary(model)
predict(model,data.frame(BrainV = 870),interval="interval")
summary(model) Call: lm(formula = IQ ~ BrainV) Residuals: Min 1Q Median 3Q Max -38.718 -18.870 9.529 16.373 27.069 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 24.18350 76.38158 0.317 0.755 BrainV 0.09884 0.08837 1.119 0.278 Residual standard error: 21.53 on 18 degrees of freedom Multiple R-squared: 0.06499, Adjusted R-squared: 0.01305 F-statistic: 1.251 on 1 and 18 DF, p-value: 0.278 > predict(model,data.frame(BrainV = 870),interval="prediction") fit lwr upr 1 110.176 63.80803 156.544 |
|
|
hence 95% prediction interval is (63.808,156.544)
f) This statement is not correct
correlation does not imply causation
3. [25 marks] Some female psychology students were investigating whether intelligence depends on brain size. They each t...
3. [25 marks] Some female psychology students were investigating whether intelligence depends on brain size. They each took a standard test that measured verbal IQ and also underwent an MRI scan to measure their brain size. The resulting data is below. IQ BrainV 132 816.932 132 951.545 90 928.799 136 991.305 90 854.258 129 833.868 120 856.472 100 878.897 71 865.363 132 852.244 112 808.02 129 790.619 86 831.772 90 798.612 83 793.549 126 866.662 126 857.782 90 834.344 129...
3. [25 marks] Some female psychology students were investigating whether intelligence depends on brain size. They each took a standard test that measured verbal IQ and also underwent an MRI scan to measure their brain size. The resulting data is below, file named IQBrain.csv. IQ BrainV 132 816.932 132 951.545 90 928.799 136 991.305 90 854.258 129 833.868 120 856.472 100 878.897 71 865.363 132 852.244 112 808.02 129 790.619 86 831.772 90 798.612 83 793.549 126 866.662 126 857.782...
3. [25 marks] Some female psychology students were investigating whether intelligence depends on brain size. They each took a standard test that measured verbal IQ and also underwent an MRI scan to measure their brain size. The resulting data is below, file named IQBrain.csv. IQ BrainV 132 816.932 132 951.545 90 928.799 136 991.305 90 854.258 129 833.868 120 856.472 100 878.897 71 865.363 132 852.244 112 808.02 129 790.619 86 831.772 90 798.612 83 793.549 126 866.662 126 857.782...
Some female psychology students were investigating whether intelligence depends on brain size. They each took a standard test that measured verbal IQ and also underwent an MRI scan to measure their brain size. The resulting data are in the file IQBrain.csv. The variables are IQ Result of the verbal IQ test. IQ is measured on an artificial index scale, usually meant to have an average value of 100. BrainV Brain volume measured in thousands of ‘pixels’. The size of a...
answer that i can understand well please Question 4 5 points Save Answer Researchers wondered whether the size of a person's brain was related to the individual's mental capacity They selected a sample of right-handed Anglo introdu psychology students who had Scholastic Aptitude Test scores higher than 1350. The subjects were administered the Wechsler Adult Intelligence Scale-Revised to obtain their IQ scores. The MRI scans, performed at the same facility, consisted of 18 horizontal MR images. The comp of the...
Researchers wondered whether the size of a person's brain was related to the individual's mental capacity. They selected a sample of 5 females and 5 males and measured their MRI image pixel counts and IQ scores. The data is reported to the right Complete parts (a) through (d) below EEB Click the icon to view the critical values table Females MRI Males IQ 833868 131,001,121 140 790,619 135 ,079,550 141 857,782 133 924.059 135 951,545 37 935,494 141 991,305 13...