In a study of reaction times to a specific stimulus, a psychologist recorded these data (in seconds). Find the variance and standard deviation. Use a TI-83 Plus/TI-84 Plus calculator and round the answers to at least two decimal places.

s² = 0.7965

s = 0.8925

Step-by-step explanation:

Given the data :

Class limit __ midpoint(x) ___ Frequency

2.1 - 2.7 2.4 13

2.8 - 3.4 3.2 14

3.5 - 4.1 3.8 10

4.2 - 4.8 4.5 6

4.9 - 5.5 5.2 2

5.6 - 6.2 5.9 1

The midpoint was calculated thus :

(Upper limit + lower limit) / 2

Using a graphing calculator :

The sample variance, s² = 0.7965

The sample standard deviation, s = 0.8925

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.

it is not that hard all u have to do is plot the graph

step-by-step explanation: