Astudy looked at n=238 adolescents, all free of severe illness.23 subjects wore a wrist actigraph, which allowed the researchers to estimate sleep patterns. those subjects classified as having low sleep efficiency had an average systolic blood pressure that was 5.8 millimeters of mercury (mm hg) higher than that of other adolescents. the standard deviation of this difference is 1.4 mm hg. based on these results, test whether this difference is significant at the 0.01 level.

Step-by-step explanation:

Since n < 30, we will find the t-score and compare that to the t-score of a significance level of 1%.    

Since they are asking if the difference is significant, we will have a two tailed test, with degree of freedom being 22, so our critical values are

t < -2.704 and t > 2.704

Our t-value for this situation is

t = ([µ + 5.8] - µ)/(1.4/√23)

It's µ + 5.8 because the problem told us that their levels are 5.8 mm higher than the average, so it's the average, plus 5.8

Simplify the equation...

t = 5.8/(1.4/√23)

t = 19.868

19.868 > 2.704, the evidence supports that there is significant difference between the sample and the population

stew reads at the fastest rate of 265 words per minute.

step-by-step explanation:

it's a given that felicia reads at 260 word per minute and on connie's graph we can see that she reads 200 words per minute. since stew's table tells us that he read 795 in 3 minutes, we can divide 795 by 3 to find out how many words he reads per minute.

795/3 = 265

stew reads 265 words per minute - he reads at the fastest rate since felecia reads at 260 words per minute and connie reads at 200 words per minute.

stew (265) > felecia (260) > connie (200)