A distribution has $\mu =100$ and $\sigma =15$. An observation of $x=145$ is ________ standard deviations above the mean.

A dataset representing the daily commute times of $25$ employees has a mean $\mu =40\text{ minutes}$ and a standard deviation $\sigma =10\text{ minutes}$. If $5$ additional employees are included in the survey, and all of them have a commute time of exactly $40\text{ minutes}$, which of the following statements best describes the effect on the dataset?

A dataset has a mean $\mu =50$ and a standard deviation $\sigma =8$. A value $x$ is considered "within 1 standard deviation" if it falls in the interval ________.

If a height dataset is normally distributed with $\mu =170\text{ cm}$ and $\sigma =10\text{ cm}$, about 68% of the heights will be between ________.

When comparing the consistency of two manufacturing processes for producing engine parts, which statistic provides a direct measure of the "predictability" or "typical clustering" of the output size in the original units of measurement (e.g., millimeters)?