Answer:
Step-by-step explanation:
You don't need the Law of Cosines, the Law of sines if what you need. You can't use the Law of Cosines because in order to find side a, you would need the length of side c and you don't have it. Using the Law of Sines is appropriate, knowing that angle B = 55:
and solving for a:
so
a = 143.0
Answer:
For this case the statistic calculated is
So the p value is a very high value and using the significance level given we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and there is enough evidence to conclude that we have a difference between the two means at 10% of significance.
Step-by-step explanation:
Data given and notation
represent the mean for the sample for A
represent the mean for the sample B
represent the sample standard deviation for the sample A
represent the sample standard deviation for the sample B
sample size for the group poisoned
sample size for the group unpoisoned
t would represent the statistic (variable of interest)
Concepts and formulas to use
We need to conduct a hypothesis in order to check if the two means are equal or not , the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
For this case is better apply a t test to compare means, and the statistic is given by:
(1)
t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.
Calculate the statistic
For this case the statistic calculated is
Statistical decision
The significance level is 0.1 , but we can calculate the p value for this test. The first step is calculate the degrees of freedom, on this case:
The p value on this case is given
So the p value is a very high value and using the significance level given we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and there is enough evidence to conclude that we have a difference between the two means at 10% of significance.