A study was designed to investigate the effects of two variables long dash (1) a student's level of mathematical anxiety and (2) teaching method long dash 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 250 with a standard deviation of 40 on a standardized test. Assuming a mound-shaped and symmetric distribution, in what range would approximately 99.7% of the students score?

99.7% of the students would fall between 130 and 370.

Using the empirical rule we know that 99.7% of the data falls within 3 standard deviations of the mean. The standard deviation is 120, so this means our range is from 250-120 to 250+120, or 130 to 370.

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JeanaShupp JeanaShupp · Answer 2 · 2019-08-23T09:28:59+02:00

Answer: [tex](130,\ 370)[/tex]

Step-by-step explanation:

Given : Sample Mean score : [tex]\overline{x}=250[/tex]

Standard deviation : [tex]\sigma=40[/tex]

The range that would represent the approximately 99.7% of the students score :-

[tex]\overline{x}\pm 3\sigma[/tex]

i.e. [tex]250\pm 3(40)/tex]

i.e. [tex]250\pm 120/tex]

[tex]=(250-120,\ 250+120)=(130,\ 370)[/tex]

Hence, the range that represents the approximately 99.7% of the students score = [tex](130,\ 370)[/tex]