Question

An article in Human Factors (June 1989) presented data on visual accommodation (a function of eye movement) when recognizing a .speckle pattern on a high-resolution CRT screen. The data are as follows: 36.45, 67.90. 38.77. 42.18, 26.72, 50.77, 39.30, and 49.71. Calculate the sample average and sample standard deviation. Construct a dot diagram of the data.

Answer 1

Answer:

Step-by-step explanation:

Hello!

The variable of interest is:

X: visual accommodation when recognizing a speckle pattern of high-resolution CRT screen.

n= 8

Aux calculations:

∑X= 351.80

∑X²= 16528.40

To calculate the sample mean (X[bar]) you have to use the followinf formula:

X[bar]= ∑X/n= 351.80/8= 43.98

The standard deviation (S) is the square root of the variance(S²), so the first step is to calculate the variance and then the standard deviation.

S²= $\frac{1}{n-1}*[sumX^2-\frac{(sumX)^2}{n} ]$

S²= $\frac{1}{7}*[16528.40-\frac{(351.80)^2}{8} ]$

S²= 151.14

S=√S²= 12.29

Diagram attached.

I hope it helps!