Question 1188837
i'm not sure if this is right, but here goes.
the standard deviation for the population is assumed to be 2.3 ounces.
with a sample size of 20, the standarfd error is 2.3 / sqrt(20) = .514296 rounded to 6 decimal places.
z-score = (x - m) / s
x is the mean of the sample.
m is the mean of the population.
s is the standard error.
formula becomes:
z = (1.9 - 2.3) / .514296 = -.77776 rounded to 5 decimal places.
critical z-score at one-tailed signjificance level of .05 is equal to -1.645.
since the test z-score is less than that, there is not sufficient information to say that the population standard deviation is less than 2.3.