Answer:
Step-by-step explanation:
Given that an investigator measuring various characteristics of a large group of athletes found that the correlation between the weight of an athlete and the amount of weight that athlete could lift was 0.60.
Correlation coefficient is the measure of association and a positive value implies that increase in one value causes increase in the other.
Hence out of the given options correct ones are
c) The more an athlete weights, on the average the more he weights.
d) The more an athlete can lift, on the average the more he weighs.
e) 60% of athlete's lifting ability can be attributed to his weight alone.
-5/10 this simplifies to -2/5
Recall your d = rt. distance = rate * time.
let's say the speed of the current is "c".
keeping in mind that, when the boat is going against the current, the boat is not really going at 2kmh, but instead at " 20 - c ", because the current is subtracting speed from it.
Likewise when is going with the current, is going at a speed of " 20 + c ".
if the boat took say "t" hours on the way over, on the way back it took the slack from the whole 8 hours and "t", namely it took " 8 - t " hours.
![\bf \begin{array}{lccclll} &\stackrel{km}{distance}&\stackrel{kmh}{rate}&\stackrel{hours}{time}\\ &------&------&------\\ \textit{against the current}&20&20-c&t\\ \textit{with the current}&180&20+c&8-t \end{array} \\\\\\ \begin{cases} 20=(20-c)(t)\implies \frac{20}{20-c}=t\\ 180=(20+c)(8-\stackrel{\downarrow }{t})\\ --------------\\ 180=(20+c)\left( 8- \stackrel{\downarrow }{\frac{20}{20-c}}\right) \end{cases} \\\\\\ 180=(20+c)\left( \cfrac{(160-8c)-20}{20-c} \right)](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Blccclll%7D%0A%26%5Cstackrel%7Bkm%7D%7Bdistance%7D%26%5Cstackrel%7Bkmh%7D%7Brate%7D%26%5Cstackrel%7Bhours%7D%7Btime%7D%5C%5C%0A%26------%26------%26------%5C%5C%0A%5Ctextit%7Bagainst%20the%20current%7D%2620%2620-c%26t%5C%5C%0A%5Ctextit%7Bwith%20the%20current%7D%26180%2620%2Bc%268-t%0A%5Cend%7Barray%7D%0A%5C%5C%5C%5C%5C%5C%0A%5Cbegin%7Bcases%7D%0A20%3D%2820-c%29%28t%29%5Cimplies%20%5Cfrac%7B20%7D%7B20-c%7D%3Dt%5C%5C%0A180%3D%2820%2Bc%29%288-%5Cstackrel%7B%5Cdownarrow%20%7D%7Bt%7D%29%5C%5C%0A--------------%5C%5C%0A180%3D%2820%2Bc%29%5Cleft%28%208-%20%5Cstackrel%7B%5Cdownarrow%20%7D%7B%5Cfrac%7B20%7D%7B20-c%7D%7D%5Cright%29%0A%5Cend%7Bcases%7D%0A%5C%5C%5C%5C%5C%5C%0A180%3D%2820%2Bc%29%5Cleft%28%20%5Ccfrac%7B%28160-8c%29-20%7D%7B20-c%7D%20%5Cright%29)
If you got this answer from a calculator, it rounds the last decimal point because there is not enough room on it to show that it is a repeating decimal.
Really, the decimal is .666666666666...... , or 2/3
This is one of the most common repeating decimals that will come up in later math practices. It would be a helpful conversion to memorize.
Hope this helped!! :)
21+3x=-15
3x=-15-21
3x=-36
x=-36/3
x=-12