# Chapter 6 | Exercise 1

Make a scatter plot and add a regression line of log-transformed frequencies (add 1 to the scores to avoid –Infinity) and mean reaction times in the data set `ldt`

. What is the relationship between the variables? Remove the outliers with reaction times greater than 1200 ms and repeat the procedure. What has changed?

Load the package and the data:

```
> library(Rling)
> data(ldt)
```

Make a scatter plot and add a regression line:

```
> plot(ldt$Mean_RT ~ log1p(ldt$Freq))
> m <- lm(ldt$Mean_RT ~ log1p(ldt$Freq))
> abline(m)
```

The relationship is inverse (the higher the frequencies, the lower the reaction times).

```
> ldt1 <- ldt[ldt$Mean_RT < 1200, ]
> m1 <- lm(ldt1$Mean_RT ~ log1p(ldt1$Freq))
> abline(m1, lty = 2)
```

The slope of the new regression line is slightly less steep.