E=Z*sqrt (p(1-p)/N), where E= error margin, p=proportion, N=sample size
Katrina's margin error at 85% confidence interval: E=1.96*sqrt (p(1-p)/100) = 0.196 sqrt (1(1-p))
Mathew's margin error at 99% confidence interval: E= 2.58*sqrt (p(1-p)/400) = 0.129 sqrt (p(1-p))
Since both obtained same estimate of proportion (that is, value of p), it can be seen that Mathew's estimate will have a small error (That is, 0.129 is smaller than 0.196). This can be attributed to larger sample size although a wider confidence (99%) interval was considered.
The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Learn more about arithmetic sequence here:
brainly.com/question/25749583
#SPJ1
Step-by-step explanation:
are you talking about like 24/7 ? or you mean like divide 24÷7 ?
Answer:
A
Step-by-step explanation:
(5x4) - 6 / 2 = x
<h3>
Answer: 5 < x < 29</h3>
=========================================
Explanation:
Since AB is smaller than AD, this must mean the angle ACB is smaller than angle ACD. Note how these angles are opposite the sides mentioned.
So 2x-10 < 48
At the same time, 2x-10 is also larger than 0.
Overall, we can say 0 < 2x-10 < 48
---------
Let's solve for x
0 < 2x-10 < 48
0+10 < 2x < 48+10 ...... add 10 to all sides
10 < 2x < 58
10/2 < x < 58/2 ..... divide all sides by 2
5 < x < 29
