Answer:
3 √5
Step-by-step explanation:
C your welcome tell me if u need more help
Answer:
3000 meters
Step-by-step explanation:
1 kilometer = 1000 meters
1 kilometers = every 20 minutes
3× 1000 meters= 20 min ×3
3000 meters = 60 min/ 1 hour
Answer:
Answer is c
Step-by-step explanation:
In hypothesis testing whether to accept or reject null hypothesis, normally we find one method as using confidence interval. If the test statistic lies within confidence interval, we accept otherwise we reject.
For arriving confidence intervals we add and subtract margin of error from the mean we use in null hypothesis.
Margin of error = std error * critical value of test (Z or t etc)
For the same std deviation, std error = std dev/sq rt of sample size
Thus std error is inversely proportional to the square root of sample size.
If n becomes larger, std error becomes smaller and vice versa.
So margin of error increases for smaller sample size.
Since we have to select confidence level from a small sample, we have to select one which has the greatest margin of error=18
Hence answer is
c) 71%(+/-18%)
The sum of any arithmetic sequence is the average of the first and last terms times the number of terms.
Any term in an arithmetic sequence is:
a(n)=a+d(n-1), where a=initial term, d=common difference, n=term number
So the first term is a, and the last term is a+d(n-1) so the sum can be expressed as:
s(n)(a+a+d(n-1))(n/2)
s(n)=(2a+dn-d)(n/2)
s(n)=(2an+dn^2-dn)/2
However we need to know how many terms are in the sequence.
a(n)=a+d(n-1), and we know a=3 and d=2 and a(n)=21 so
21=3+2(n-1)
18=2(n-1)
9=n-1
10=n so there are 10 terms in the sequence.
s(n)=(2an+dn^2-dn)/2, becomes, a=3, d=2, n=10
s(10)=(2*3*10+2*10^2-2*10)/2
s(10)=(60+200-20)/2
s(10)=240/2
s(10)=120
