PSY325: Statistics for the Behavioral & Social Sciences (PSI1414A) – Essay Example

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In addition, this correlation also provides evidence that high IQ causes GPA to go higher. Correlation is just a measure of inter relationship between two variables whereas causation is a functional relationship between two variables (one influencing the other). Sample Size is a key factor that affects the size of this correlation. Importantly, yes, correlation a good test for predicting GPA. Essay 3 The above analysis was run with MS Excel. The following results were obtained: Descriptive Statistics of Reaction time Mean 6.36 Standard Error 0.758995 Median 6.05 Mode 9.5 Standard Deviation 3.39433 Sample Variance 11.52147 Kurtosis 0.578947 Skewness 0.775233 Range 13 Minimum 2.2 Maximum 15.2 Sum 127.2 Count 20 Confidence level (95%) 1.588595 The above table shows that the mean reaction time is 6.36 with Standard Deviation 3.39 and the standard error being 0.76.

The 95% confidence interval is 6.36+1.59 ie. (4.77,7.95). Answer: The data is arranged in ascending order and divided into two groups each containing 10 values. I sample (low reaction) 2.2 2.5 2.7 2.9 3.1 3.5 4.1 4.3 4.7 4.8 II sample (high reaction) 7.3 7.6 8.1 8.2 8.5 9.2 9.3 9.5 9.5 15.2 The descriptive statistics for each group is given below: Descriptive Statistics: Lower reaction time Mean 3.480 95% Confidence Interval for Mean Lower Bound 2.807 Upper Bound 4.153 Standard Error 0.2977 Median 3.300 Variance. 886 Std. Deviation. 9414 Minimum 2.2 Maximum 4.8 Range 2.6 Interquartile Range 1.8 Skewness. 190 Kurtosis -1.571 Interpretation: From the above table, it is observed that mean of the lower reaction group is 3.48 with standard deviation 0.9414 and standard error 0.2977.

The 95% confidence interval is (2.807,4.153). The outliers are 2.2, 2.5, 2.7, 4.3, 4.7, 4.8. This shows that the outliers are above 50% which shows the data has high variability and if the sample size is increased, this may lead to the variability less. Descriptive Statistics: Higher reaction time Mean 9.240 95% Confidence Interval for Mean Lower Bound 7.640 Upper Bound 10.840 Standard Error 0.7075 Median 8.850 Variance 5.005 Std. Deviation 2.2372 Minimum 7.3 Maximum 15.2 Range 7.9 Interquartile Range 1.5 Skewness 2.444 Kurtosis 6.869 Interpretation: From the above table, it is that mean of the higher reaction group is 9.24 with standard deviation 2.2372 and standard error 0.7075. The 95% confidence interval is (7.64,10.84).

The outliers are 7.3, 7.6 and 15.2. This shows that the outliers are 30% which shows the data has less variability and if the value 15.2 is excluded; all the data values will be within the 95% confidence interval.

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