MQ3

Which of the following events is the most probable?

flipping 6 or more heads in 10 coin flips (less)

In a single day, 45 babies were born in hospital X, 65 babies in hospital Y, and 25 babies in hospital Z. At which hospital is there the greatest probability that more than 60 percent of the babies are of the same sex?

hospital Z

Which of the following provides the best guidance on the significance of an observed difference between two research samples?

inferential statistics

Which measure of central tendency is used to calculate the average of your school grades?

mean

The median of a distribution of scores is the

middle score in a distribution of scores.

A normal curve would approximate the distribution of -males and females in the total American population. - American children enrolled in each of the first through sixth grades. - the physical heights of all American women. - all of these data.

the physical heights of all American women.

During the last Central High School basketball game, the starting five players scored 11, 7, 21, 14, and 7 points, respectively. For this distribution of scores, the range is

14.

Approximately 95 percent of the cases represented by the normal curve fall within ________ standard deviation(s) from the mean.

2

If a set of standardized test scores is normally distributed, having a mean of 50 and a standard deviation of 10, approximately 68 percent of the group members receive scores somewhere between

40 and 60.

During the past year, Zara and Ivan each read 2 books, but George read 9, Ali read 12, and Marsha read 25. The median number of books read by these individuals was

9

________ means that the observed differences between scores is probably not due to chance variation between the samples.

Statistical significance

The mean of a distribution of scores is the

arithmetic average of all the scores.

When an arithmetic average is reported in the news, it is most important for readers to

consider whether it is distorted by a few extreme cases.

A statistically significant difference between two sample groups is NOT likely to be -a reflection of differences between the populations they represent. -due to chance variation within and between the sample groups. -observed more than 5 percent of the time the groups are compared. -observed when the two groups are very large.

due to chance variation within and between the sample groups.

As the size of a representative sample increases, the ________ of that sample is most likely to decrease.

standard deviation