In: Statistics and Probability
A researcher tests H0: p = 0.30 versus H1: p > 0.30 and obtains a P-value of 0.2514. What is the value of the standardized (z) test statistic? (Record your answer accurate to at least the nearest second decimal place with standard rounding.)
from the given hypotheses H0: p = 0.30 versus H1: p > 0.30 it is seen that the test is a one-tailed test, which is actually a right-tailed test.
The P-value is calculated using Z test scores similarly the Z scores can be calculated using P-values in excel by formula =NORM.S.INV(1-0.2514) or by Z table shown below.
It must be noted that the Z table shows the probability from the left and since the distribution is normal the shape of the distribution is symmetrical so, the same values can be used for right side values changing the sign to positive.
The Z score will be:
Z=0.67