A statistics professor was interested in using final lab grades to predict final course grades. She found the following descriptive statistics. Grades are reported as percentages. average lab grade = 75, SD = 20
average final grade= 80, SD = 15, r = 0.60
a) What is the slope of the regression line for her predictions?
b) What is the intercept of the regression line for her predictions?
c) What is the RMS error for her predictions?
d) Predict the final grade for students who earned an 85% in lab.
e) Predict the final grade for students who earned a 65% in lab.
f) Report the percent of students who are predicted to have final grades between 68% and 92%.
g) Select the correct discription.
1. The strength of the correlation may be overemphasized because of the use of rates.
2. This correlation represents an accurate assessment of the effect of lab grades on final grades.
3. A student who skips the labs is predict to have a passing final grade (70% or above).
4. All of the above are true.

6,250

step-by-step explanation:

to get the area, multiply 360 by 160.(57,600)

to find out how many bags of fertilizer it will take, first figure out how many square feet one bag can hold. divide 1000 by 8(125) to get the unit rate(how many square feet one pound of fertilizer can hold)and multiply it by 50(6250). if i haven't made a mistake, that is the answer.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

363 square inches

step-by-step explanation:

surface area of a pyramid is b + 1/2ph

b is the area of the base: 11 x 11 = 121

p is the perimeter of the base: 11 + 11 + 11 + 11 = 44

h is the height of the pyramid: 11

121 + 1/2(44)(11)

121 + 242

363