Update _01-sa-data-hello.qmd (#519)

Corrected definition of PM10. Modified the text about air quality measurements for accuracy in environmental science.

Author: e-linc

exercises/_01-sa-data-hello.qmd

@@ -1,7 +1,7 @@
 1.  23 observations and 7 variables.
 \addtocounter{enumi}{1}
 
-1.  \(a\) "Is there an association between air pollution exposure and preterm births?" (b) 143,196 births in Southern California between 1989 and 1993. (c) Measurements of carbon monoxide, nitrogen dioxide, ozone, and particulate matter less than 10$\mu g/m^3$ (PM$_{10}$) collected at air-quality-monitoring stations as well as length of gestation. Continuous numerical variables.
+1.  \(a\) "Is there an association between air pollution exposure and preterm births?" (b) 143,196 births in Southern California between 1989 and 1993. (c) Concentrations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with an aerodynamic diameter of 10 micrometres or less (PM$_{10}$) measured at air quality monitoring stations as well as length of gestation. Continuous numerical variables.
 \addtocounter{enumi}{1}
 
 1.  \(a\) "What is the effect of gamification on learning outcomes compared to traditional teaching methods?" (b) 365 college students taking a statistics course (c) Gender (categorical), level of studies (categorical, ordinal), academic major (categorical), expertise in English language (categorical, ordinal), use of personal computers and games (categorical, ordinal), treatment group (categorical), score (numerical, discrete).