Answer:
The correct option is A
Step-by-step explanation:
From the question we are told that
The population is 
The level of significance is 
The sample data is 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds
The Null hypothesis is 
The Alternative hypothesis is 
The critical value of the level of significance obtained from the normal distribution table is

Generally the sample mean is mathematically evaluated as

substituting values


The standard deviation is mathematically evaluated as
![\sigma = \sqrt{\frac{\sum [ x - \= x ]}{n} }](https://tex.z-dn.net/?f=%5Csigma%20%20%3D%20%20%5Csqrt%7B%5Cfrac%7B%5Csum%20%20%5B%20x%20-%20%20%5C%3D%20x%20%5D%7D%7Bn%7D%20%7D)
substituting values
![\sigma = \sqrt{\frac{ [ 9.0-7.5571]^2 + [7.3 -7.5571]^2 + [6.0-7.5571]^2 + [8.8- 7.5571]^2 + [6.8- 7.5571]^2 + [8.4 - 7.5571]^2+ [6.6- 7.5571]^2 }{7} }](https://tex.z-dn.net/?f=%5Csigma%20%20%3D%20%20%5Csqrt%7B%5Cfrac%7B%20%20%5B%209.0-7.5571%5D%5E2%20%2B%20%5B7.3%20-7.5571%5D%5E2%20%2B%20%5B6.0-7.5571%5D%5E2%20%2B%20%5B8.8-%207.5571%5D%5E2%20%2B%20%5B6.8-%207.5571%5D%5E2%20%2B%20%5B8.4%20-%207.5571%5D%5E2%2B%20%5B6.6-%207.5571%5D%5E2%20%7D%7B7%7D%20%7D)

Generally the test statistic is mathematically evaluated as

substituting values


Looking at the value of t and
we see that
hence we fail to reject the null hypothesis
What this implies is that there is no sufficient evidence to state that the sample data show as significant increase in the average birth rate
The conclusion is that the mean is 