A study was designed to investigate the effects of two variables−(1) a student's level of mathematical anxiety and (2) teaching method−on a student's achievement in a mathematics course. Students who had a low level of mathematical anxiety were taught using the traditional expository method. These students obtained a mean score of 340 with a standard deviation of 30 on a standardized test. Assuming no information concerning the shape of the distribution is known, what percentage of the students scored between 280 and 400?

answer: the answer is one of

step-by-step explanation:   we are given to write a proper fraction where the whole is divided into an even number of equal parts less than ten, and an odd number of those parts exist.

an even number less than 10 may be one of 2, 4, 6 or 8. so, the whole may be one of these four evens.

now, an odd number of these parts must exist, so the numerator must be an odd number, one of 1, 3, 5 or 7. it cannot be 9 because then the fraction will become improper.

thus, our fraction may be one of the following

b

2

−

b

b

3

+

7

b

2

+

14

b

+

6

%

−

3

b

3

+

7

b

2

+

14

b

+

6

%

step-by-step explanation:

the answer is 1030 it's very simple math.

answer: 1.06 km per sec

step-by-step explanation:

39.6 m=63.72 km

60 min in an hour so 63.72/60=1.06