First, we need to calculate the sample proportion of articles with US authors:
p-hat = 82/255
p-hat = 0.3216
Next, we calculate the standard error of the sample proportion:
SE = sqrt((0.39*(1-0.39))/255)
SE = 0.0273
Now, we can calculate the z-score of the sample proportion:
z = (0.3216 - 0.39)/0.0273
z = -2.5201
Therefore, the value of the test statistic is -2.52 (rounded to two decimal places).
he National Academy of Science reported that 39%
of research in mathematics is published by US authors. The mathematics chairperson of a prestigious university wishes to test the claim that this percentage is no longer 39%
. He has no indication of whether the percentage has increased or decreased since that time. He surveys a simple random sample of 255
recent articles published by reputable mathematics research journals and finds that 82
of these articles have US authors. Does this evidence support the mathematics chairperson’s claim that the percentage is no longer 39%
? Use a 0.01
level of significance.
Step 2 of 3: Compute the value of the test statistic. Round your answer to two decimal places.
1 answer