The answer is the top option.
8 ÷ (2 3/4) = 32/11
248 ÷ (32/11) = B. 85 1/4 cubic feet
Answer:
The claim made by the researcher lacks the validity on basis of reasons as indicated in the explanation.
Step-by-step explanation:
The claim made by the researcher is not valid on basis of following reasons:
- Interacting variables are not mapped accurately. The additional variables as the health status of the volunteers, eating and fitness habits are not considered in the consideration. This results in a in complete validation.
- The placebo effect is not catered accordingly. As the half of the volunteers are taking nothing, this is not the direct influence of the placebo and thus double-blinded testing for placebo effect is to be ensured in future experiments.
- The environmental effects are not considered as the effect under study is dependent on the environmental effects, thus the claim is biased and the generalization is not valid.
Answer:
B. z Subscript alpha divided by 2 zα/2 = 1.96.
Step-by-step explanation:
We are given that we want to construct a confidence interval. For this, the summary statistics for randomly selected weights of newborn girls:
n = 236, 
= 30.3 hg, s = 7.2 hg. The confidence level is 95%.
As we can clearly see here that the population standard deviation is unknown and the sample size is also very large.
It has been stated that when the population standard deviation is unknown, we should use t-distribution but since the sample size is very large so we can use z distribution also as it is stated that at very large samples; the t-distribution corresponds to the z-distribution.
Here, 
= level of significance = 1 - 0.95 = 0.05 or 5%
= 0.025 or 2.5%
So, the value of 
in the z table is given as 1.96 with a 2.5% level of significance.
Angles 7, 6, 3, 2 are all vertical angles, which mean they are congruent (equal)
so if angle 7 is 115° so are 6, 3, and 2
so the measure of angle 2 is 115°
