91影视

The sample of human brain volumes in centimeter cube from data set 8 鈥淚Q and Brain size鈥� in Appendix B.

The given sample data arrange in increasing order as:

963, 1027, 1029, 1034, 1070, 1079, 1079, 1439.

In the given data, the sample size is 8. Each value is the proportion of $\frac{1}{8}$of the sample.

So, the cumulative left areas, can be expressed as $\frac{1}{2n},\frac{3}{2n},\frac{5}{2n},鈥�\text{and}鈥�鈥�\text{so}鈥�鈥�\text{on}$.

For the given sample size,$\text{n}=8$ , the cumulative left areas can be expressed as

$\frac{1}{16},\frac{3}{16},\frac{5}{16},\frac{7}{16},\frac{9}{16},\frac{11}{16},\frac{13}{16}鈥�\text{and}鈥�\frac{15}{16}$

The cumulative left areas expressed in decimal form are 0.0625, 0.1875, 0.3125, 0.4375, 0.5625, 0.6875, 0.8125, and 0.9375.

Refer to the standard normal distribution table, the z-score value corresponding to 0.0625, 0.1875, 0.3125, 0.4375, 0.5625, 0.6875, 0.8125 and 0.9375 for a left-tailed test is equal to -1.53, -0.89, -0.49, -0.16, 0.16, 0.49, 0.89, 1.53.

Pair thesample values of human brain volume with the corresponding z-score in the form of (x, y) as:

(963-1.53), (1027,-0.89),(1029,-0.49), (1034,-0.16), (1070,0.16),

(1079, 0.49), ( 1079, 0.89), and (1439,1.53)

Steps to draw a Normal quantile plot are as follows:

1. Make horizontal axis and vertical axis.
2. Mark the points 32, 33.3, 34.9 up to 45 on the horizontal axis and points -1.3, -1.04, -0.78, up to 1.3.
3. Provide title to horizontal and vertical axis as 鈥淴 values鈥� and 鈥淶-score鈥� respectively.
4. Mark the co-ordinates and obtain the graph as shown below.

From the normal quantile plot, the points do not show any symmetric pattern. So, the sample of human brain volume does not appear to be from a normally distributed population.