The question in English
<span>Each of the 25 students in the class has made a journal on Monday. Knowing that every day a page was used and that the month is 31 days, find out how many pages the logs of all students.
</span>Let
x--------------> total students
y--------------> total days in a month
z--------------> total page used per one student in 1 day
T--------------> total page used per total students in 1 month
we know that
x=25 students
y=31 pages
z=1 page
T=[x]*[y]*[z]------------> T=[25]*[31]*[1]------------> T=775 pages
the answer is 775 pages
<span>the answer in Romanian
</span>
lăsa
x--------------> numărul total de elevi
y--------------> <span>total zile într-o lună
</span>z--------------> <span>pagina totală utilizată pentru un student în 1 zi
</span>T--------------> pagina totală utilizată pentru toți elevii în 1 lună
noi stim aia
x=25 elevi
y=31pagini
z=1 pagină
T=[x]*[y]*[z]------------> T=[25]*[31]*[1]------------> T=775 pagini
răspunsul este de 775 de pagini
Bivariate data contains two variables
Answer:
a) r=-0.719
b) y=10.642-0.976x
c)Predicted y=7.714
Step-by-step explanation:
a)
sumx=1+4+6+7=18
sumy=9+7+8+1=25
sumxy=1*9+4*7+6*8+7*1=92
sumx²=1²+4²+6²+7²=102
sumy²=9²+7²+8²+1²=195
n=number of observation=4
The correlation coefficient is computed by following formula
![r=\frac{nsumxy-(sumx)(sumy)}{\sqrt{[nsumx^{2} -(sumx)^2][nsumy^2-(sumy)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bnsumxy-%28sumx%29%28sumy%29%7D%7B%5Csqrt%7B%5Bnsumx%5E%7B2%7D%20-%28sumx%29%5E2%5D%5Bnsumy%5E2-%28sumy%29%5E2%5D%7D%7D)
![r=\frac{4(92)-(18)(25)}{\sqrt{[4(102) -(18)^2][4(195)-(25)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B4%2892%29-%2818%29%2825%29%7D%7B%5Csqrt%7B%5B4%28102%29%20-%2818%29%5E2%5D%5B4%28195%29-%2825%29%5E2%5D%7D%7D)
![r=\frac{368-450}{\sqrt{[408 -324][780-625]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B368-450%7D%7B%5Csqrt%7B%5B408%20-324%5D%5B780-625%5D%7D%7D)
![r=\frac{-82}{\sqrt{[84][155]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B-82%7D%7B%5Csqrt%7B%5B84%5D%5B155%5D%7D%7D)
By rounding r to 3 decimal places we get r=-0.719.
b)
The regression equation can be written as y=a+bx
We have to find "a" and "b" for regression equation
b=-0.976
xbar=sumx/n
xbar=18/4=4.5
ybar=sumy/n
ybar=25/4=6.25
a=ybar-b(xbar)
a=6.25-(-0.976)4.5
a=6.25+4.392
a=10.642
Thus, the regression equation is
y=a+bx
y=10.642-0.976x
c)
The predicted value of y for x=3 can be computed by putting the value of x in regression equation
y=10.642-0.976(3)
y=10.642-2.928
y=7.714
Hence, the predicted y-value for x=3 is 7.714.
Answer:
D
Step-by-step explanation:
there isn't much of a harsh trend, but the graph shows that generally when the unemployment is lower, the life expectancy is higher, and when the unemployment is higher, the life expectancy is lower.
