Answer:
The 95% confidence interval for the percent of all coffee drinkers who would say they are addicted to coffee is between 21% and 31%.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
A confidence interval has two bounds, the lower and the upper
Lower bound:
Upper bound:
In this problem, we have that:
Lower bound:
Upper bound:
The 95% confidence interval for the percent of all coffee drinkers who would say they are addicted to coffee is between 21% and 31%.
Answer:
f(-4)= -55
Step-by-step explanation:
We want to find f(x), or y, when x is equal to -4.
Therefore, we can substitute -4 in for x in the function.
f(x) = -2x^2 + 4x - 7
Substitute -4 in for x
f(-4) = -2(-4^2) + 4(-4) - 7
Evaluate the exponent
f(-4)=-2(16)+4(-4)-7
Multiply -2 and 16
f(-4)= -32+4(-4)-7
Multiply 4 and -4
f(-4)=-32-16-7
Subtract
f(-4)=-55
Answer:
m∠XAZ = 40°
Step-by-step explanation:
Since ∠YAU, ∠YAZ and ∠XAZ are the angles based at a point on a straight line, and the sum of the all angles on a line is 180°.
Therefore, m∠YAU + m∠YAZ + m∠XAZ = 180°
50° + 90° + m∠XAZ = 180°
m∠XAZ = 180° - 140°
= 40°
Therefore, measure of angle XAZ is 40°.
