Question

Leema's test scores in chemistry are 80, 95, 88, 92, and 100. Find the mean and standard deviation of the data. If necessary, round to the nearest tenth. Mean: ______ Standard deviation: ______

Answer 1

Answer:

Mean is 91

SD=6.8 to the nearest tenth.

Step-by-step explanation:

Leema's test scores in chemistry are 80, 95, 88, 92, and 100.

We want to find the mean and standard deviation.

The mean is given by:

$\bar X=\frac{80+95+88+92+100`}{5}$

$\bar X=\frac{455`}{5}=91$

The standard deviation is given by:

$SD=\sqrt{\frac{\sum(x-\bar X)^2}{n} }$

$SD=\sqrt{\frac{(80-91)^2+(95-91)^2+(88-91)^2+(92-91)^2+(100-91)^2}{5} }$

$SD=\sqrt{\frac{1140}{25} }$

SD=6.8 to the nearest tenth.