1. In a normal distribution, the mean is at the percentile. 2. Approximately
% of the scores in a normal distribution are within two standard deviations of
the mean.
3. On a math test, Chris scored at the 85th percentile. Which statement is true?
(1) Eighty-five percent of the students who took the test had the same score as Chris.
(2) Fifteen percent of the students had scores equal to or less than Chris.
(3) Eighty-five percent of the students who took the test had scores equal to or less than Chris.
(4) Chris scored 85% on the test.
4. The scores of a math class on a statistics exam were as follows:
72
76
91
74
83
79
93
85
97
91
89
81
87
88
86
94
84
Using intervals of 71-75, 76-80,..., construct a frequency and cumulative frequency table for the
data
Interval
Frequency
Cumulative
Frequency
5. Consider the following table, what shape would the bell curve take if graphed?
Goals Scored
0
1
2
3
4
5
6
7
Frequency
4
8
5
3
1
1
0
1

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

the results from a pre-test for students for the year 2000 and the year 2010 are illustrated in the box plot. what do these results tell us about how students performed on the 29 question pre-test for the two years?

if we compare only the lowest and highest scores between the two years, we might conclude that the students in 2010 did better than the students in 2010. this conclusion seems to follow since the lowest score of 8 in 2010 is greater in value than the lowest score of 6 in 2000. also, the highest score of 28 in 2010 is greater in value than the highest score of 27 in 2000.

but the box portion of the illustration gives us more detailed information. the middle bar in each box shows us that the median score of 20 in 2000 is greater in value than the median score of 17 in 2010. further, we note that the box and whiskers divide the illustration into four pieces. each of these four pieces represents the same portion of students. so, the upper half of the students in 2000 scored in the same score range as the upper one-fourth of the students in 2010, see the illustration at a score of 20.

by considering the upper one-fourth, upper half, and upper three-fourths instead of just the lowest and highest scores, we would conclude that the students as a whole did much better in 2000 than in 2010. we would conclude that as a whole the students in 2010 are less prepared than the students in 2000.

in this section, we discuss box-and-whisker plots and the five key values used in constructing a box-and-whisker plot. the key values are called a five-number summary, which consists of the minimum, first quartile, median, third quartile, and maximum.

step-by-step explanation:

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.