Feelings of safety, security, self-esteem in children typically result from Having supportive, loving family relationships Introducing personal technology devices during the preschool years Allowing children to figure things out on their own with very little parental engagement

Show the t \( r=\frac{\sum_{i=1}^{n}\left(x_{i}-\bar{x}\right)\left(y_{i}-\bar{y}\right)}{\sqrt{\sum_{i=1}^{n}\left(x_{i}-\bar{x}\right)^{2} \sum_{i=1}^{n}(y-\bar{y})}} \)

a) \( -2-7-(-8-1) \)

Elercicio 1 [1'5 puntos] Calcua: a) \( \lim _{x \rightarrow 2} \frac{x^{2}-5 x+6}{x-2} \)

A teacher gave a 25 -question multiple-choice test. After scoring the tests, she computed a mean and standard deviation of the scores. The standard deviation was 0 . Based on this information: all of the students had the same score. about half of the scores were above the mean. the teacher must have made a mistake in her computations.

(8.) \( \lim _{x \rightarrow 0} \frac{\eta \mu x-x}{e^{x}-1} \)