Answer:
A. Fail to reject the null hypothesis.
Step-by-step explanation:
We are given with the Population mean weight of newborn infants at a community hospital, = 6.6 pounds
Now the sample data of seven infants with their weights at birth is given as:
6.0, 6.6, 6.8, 7.3, 8.4, 8.8, 9.0
Sample Mean, Xbar = where Xi are the each data value
and n = sample size
= = 7.56
Sample Standard Deviation, s = = 1.18
Let Null hypothesis, : = 6.6 pounds
Alternate hypothesis, : > 6.6 pounds
Since we don't know about population standard deviation so the test statistics we use here will be :
follows t distribution with (n-1) degree of freedom []
Test Statistics = follows
= 2.1525
<em>At 5% level of significance </em><em> has a value of 1.943 but our test statistics is higher than this so we have sufficient evidence to accept null hypothesis and conclude that mean is 6.6 pounds.</em>
Therefore, option A is correct that we Fail to reject the null hypothesis.