Question

Much concern has been expressed regarding the practice of using nitrates as meat preservatives. In one study involving possible effects of these chemicals, bacteria cultures were grown in a medium containing nitrates. The rate of up take of radio-labeled amino acid (in dpm, disintegrations per minute) was then determined for each culture, yielding the following observations:
7251 6871 9632 6866 9094 5849 8957 7978 7064 7494 7883 8178 7523 8724 7468

Suppose that it is know that the mean rate of uptake for cultures without nitrates is 8000. Do the data suggest that the addition of nitrates results in a decrease in the mean rate of uptake? Test the appropriate hypotheses using a significance level of 0.10.

Answer 1

Answer:

There is no statistical evidence to support that mean is less than 8000 at 10% level

Step-by-step explanation:

Set up hypotheses as

$H_0: \mu = 8000\\H_a: \mu$

(Left tailed test)

The data for the observations are

7251 6871 9632 6866 9094 5849 8957 7978 7064 7494 7883 8178 7523 8724 7468

From the above data we find that

$\bar x= 7788.8\\Std dev s= 968.44\\std error = \frac{s}{\sqrt{15} } =250.050$

Mean difference= -211.2

Test statistic t = mean difference/std error = -0.844

df = 14

p value= 0.20643

Since p >0.10 we accept H0

There is no statistical evidence to support that mean is less than 8000 at 10% level