Answer:
b) The width of the confidence interval becomes narrower when the sample mean increases.
Step-by-step explanation:
The confidence interval can be calculated as:

a) The width of the confidence interval becomes wider as the confidence level increases.
The above statement is true as the confidence level increases the width increases as the absolute value of test statistic increases.
b) The width of the confidence interval becomes narrower when the sample mean increases.
The above statement is false. As the sample mean increases the width of the confidence interval increases.
c) The width of the confidence interval becomes narrower when the sample size n increases.
The above statement is true as the sample size increases the standard error decreases and the confidence interval become narrower.
Answer:
The price where the manufacture sells the maximum number of toys is $20
Step-by-step explanation:
The given equation for that represents the number of toys the manufacturer can sell is given as follows;
T = -4·p² + 160·p - 305
Where;
p = The price of the toys in dollars
At the point where the manufacture sells the maxim number of toys on the graph of the equation T = -4·p² + 160·p - 305, which is the top of the graph, the slope = 0
Therefore, at the maximum point;
The slope = 0 = dT/dp = d(-4·p² + 160·p - 305)/dp = -8·p + 160
∴ -8·p + 160 = 0
160 = 8·p
8·p = 160
p = 160/8 = 20
The price where the manufacture sells the maximum number of toys is = p = 20 dollars
Answer:
what problem?
Step-by-step explanation:
Justine > Ava > Emma
12 - 7.5 = 4.5
x + (x+4.5) +(x+12) = 3x + 16.5 = 63
63-16.3 = 56.7
56.7/ 3 = 18.9
A: Emma has $ 18.9 Ava has $23.4 Justin has $30.9