Answer:
Sample mean = 7.1
Margin of error = 0.465
Step-by-step explanation:
Formula for confidence interval is;
CI = x¯ ± zE
Where;
x¯ is sample mean
z is critical value at confidence level
E is margin of error.
z for 99% Cl is 2.58
We are told the CI is 5.9 to 8.3.
Thus;
5.9 = x¯ - 2.58E - - - - (1)
8.3 = x¯ + 2.58E - - - - (2)
Add both equations together to get;
14.2 = 2x¯
x¯ = 14.2/2
x¯ = 7.1
Put 7.1 for x¯ in eq 1 to get;
5.9 = 7.1 - 2.58E
7.1 - 5.9 = 2.58E
E = 1.2/2.58
E = 0.465
Answer:
Paul earned $2.6 more interest than Monica.
Step-by-step explanation:
Giving the following information:
Monica:
Initial investment= $300
Interest rate= 4.2%
Paul:
Initial investment= $400
Interest rate= 3.8%
<u>To calculate the income earned, we need to use the following formula:</u>
I= P*r*t
P= principal
r= interest rate
t= time
Monica:
I= 300*0.042*1= $12.6
Paul:
I= 400*0.038*1= $15.2
Paul earned $2.6 more interest than Monica.
Step-by-step explanation:
Move all terms that do not contain nn from the middle section of the inequality.
−5 <n≤2 - 5 <n≤2
Create equal fractions to find the number of hours he used the health club for.
2/13=x/29.25
Then, simplify so that x is by itself.
(29.25x2)/13 = x
x= 58.5/13
x=4.5 hours