Last year, one county reported that among 3000 caucasian women (group 1) who had babies, 95 had multiples (twins, triplets, the report also stated that there were 20 multiple births to 600 african american women (group 2). does this indicate a racial difference in the likelihood of multiple births

No

Explanation:

According to the statistics, the chances that a Caucasian women will have multiples are 3.17%, while an African American women has chances of 3.33%. The chances of the women from this two different racial groups having multiples are very similar, almost identical, so it can not be said that the race is a detrimental factor in having multiples or not. The multiples have been noticed to be in much higher percentages, but that has been the case in only certain regions, so it is not based on race, but more of a regional gene pool that has those traits. Such example is Nigeria, where there is high percentage of multiples, but the people of the same race surrounding Nigeria have much lower percentages of multiples.

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.