Answer:
D) Amplitude: 2; period: π; midline: y = 1
Step-by-step explanation:
The question is much more easily answered from the graph than from the description of the graph.
The amplitude is the extent of the peak above the midline (2), or half the peak-to-peak value (4/2=2). The midline is the line halfway between the peaks (1). The period is the horizontal distance between peaks of the same polarity (π).
Answer:
(a) The proportion of tenth graders reading at or below the eighth grade level is 0.1673.
(b) The 95% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level is (0.198, 0.260).
Step-by-step explanation:
Let <em>X</em> = number of students who read above the eighth grade level.
(a)
A sample of <em>n</em> = 269 students are selected. Of these 269 students, <em>X</em> = 224 students who can read above the eighth grade level.
Compute the proportion of students who can read above the eighth grade level as follows:
The proportion of students who can read above the eighth grade level is 0.8327.
Compute the proportion of tenth graders reading at or below the eighth grade level as follows:
Thus, the proportion of tenth graders reading at or below the eighth grade level is 0.1673.
(b)
the information provided is:
<em>n</em> = 709
<em>X</em> = 546
Compute the sample proportion of tenth graders reading at or below the eighth grade level as follows:
The critical value of <em>z</em> for 95% confidence interval is:
Compute the 95% confidence interval for the population proportion as follows:
Thus, the 95% confidence interval for the population proportion of tenth graders reading at or below the eighth grade level is (0.198, 0.260).