Astudy was to be undertaken to determine if a particular training program would improve physical fitness. an srs of 31 university students was selected to be enrolled in the fitness program. one important measure of fitness is maximum oxygen uptake. measurements of oxygen uptake in untrained individuals are known to follow a normal distribution with a mean of ? = 45 ml/kg/min. the researchers wished to determine if there was evidence that their sample of students differed from the general population of untrained subjects. the measurements made on the subjects coming into this study produced a mean of = 47.4 ml/kg/min with a standard deviation of s = 5.3 ml/kg/min. if the 98% confidence interval were determined to be (45.2, 49.6) an interval, which may or may not be correct, what would the researchers conclude?
a. the true mean oxygen uptake for these students is ? = 45.b. the sample is not statistically significant at the 0.02 level. c.there would be no reason to believe the selected students come from a different population. d.at the 0.02 level of significance, there is evidence to conclude that the sample comes from a population with a mean different from ? = 45.e. the sample mean is significantly different from ? = 45 at the 0.04 level.

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

equation image indicator

x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

equation image indicator

x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

equation image indicator

x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

correct answer is c. just did it

step-by-step explanation:

hello there!

i believe the answer is

(cot2+1)/sec2=cot2

    csc2/sec2=cot2

  (1/sin2)/(1/cos2)=cot2

  (1/sin2)(cos2/1)=cot2

  cos2/sin2=cot2

  (1/tan2)=cot2

  (cot2)=(cot2)

hope this !

hyperz ^_^