Answer: The margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.
Step-by-step explanation:
Since we have given that
Sample size = 400
Mean = $357.75
Standard deviation = $37.89
At 95% confidence level, z = 1.96
We first find the margin of error.
Margin of error is given by

95% confidence interval would be

Hence, the margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.
Answer:
That would be 2/7
Step-by-step explanation:
Using substitution. x^2 +x+1 at 1 is 7
sqrt4 is 2
2/7
Answer:
-320000
Step-by-step explanation:
Given
Lost Land = 80,000 acres yearly
Duration 4 years
Required
The total change
Represent the total change with y;
y is calculated as thus;



<em>Hence, a total of 320000 acres were lost during the period</em>
compare the triangles ΔABC and ΔBCD
∡ABC = ∡BCD (given)
AB = CD (given)
BC = BC (common) } = > (SAS) ΔABC ≡ ΔBCD = > AC = BD
Answer:
1/20
Step-by-step explanation:
Remark: Not huge
Total number of Socks: 6 + 6 + 4 = 16
P(First Black Sock): 4/16 = 1/4
The second Sock needs to be discussed a bit. The number of black socks has gone down to 1 and the total will always go down by 1.
Second Sock: 3 Black / 15 Total = 3/15 = 1/5
Combined Probability: 1/4 * 1/5 = 1/20