(21.23) A study of the effect of exposure to color (red or blue) on the ability to solve puzzles used 42 subjects. Half the subjects (21) were asked to solve a series of puzzles while in a red-colored environment. The other half (21) were asked to solve the same series of puzzles while in a blue-colored environment. The time taken to solve the puzzles was recorded for each subject. The 21 subjects in the red-colored environment had a mean time for solving the puzzles of 9.64 seconds with standard deviation 3.43; the 21 subjects in the blue-colored environment had a mean time of 15.84 seconds with standard deviation 8.65. The two-sample t statistic for comparing the population means has value

There is enough statistical evidence to say that the means are different.

Step-by-step explanation:

The question is incomplete:

"The two-sample t statistic for comparing the population means has value (±0.001)."

The null and alternative hypothesis are:

The level of significance is assumed to be α=0.01.

The difference of the sample means is:

The standard deviation for the difference of the means is:

Then, the t-statistic is:

The degrees of freedom are:

With 40 degrees of freedom the t-critial for a significance of α=0.01 is t=±2.705.

As the t-statistic lies in the rejection region, the effect is significant and the null hypothesis is rejected.

There is enough statistical evidence to say that the means are different.

step-by-step explan mxfcg'k; uafwgzfgjhklhgation:

i believe the correct answer is option 4.principalities were small territories that were run by russian rulers.

which statement correctly defines principalities in northern asia in the 1200s? principalities were small territories that were run by russian rulers.

hope i could ! : )