I'm doing the same thing right now and I'm lost.
Since the trapezoid can be inscribed in a circle, that means angle B + angle D = 180 degree. Since AB is parallel to CD, then angle B + angle C = 180 degree. Therefore, angle D = angle C.
Answer:
Option A
Step-by-step explanation:
Given that in a study of the relationship between geographical mobility (number of times a person has changed residences) and number of friends, Pearson's r^2 is reported as .40.
r square, being the coefficient of determination explains the variablity of one variable due to the variability of the other. Here Mobility explains 40% variation in the number of friends is right answer.
Option B is wrong because r = ±6324, so cannot say positive or negative.
Similarly option c is wrong because we are unsure whether negative correlation. Option d is wrong since 16% is not right .
Answer:
a. There's a 95% chance that the true proportion is in the confidence interval.
Step-by-step explanation:
When we want to estimate a property of a population (a population's parameter), without surveying the population, we use samples.
Then, with the information of the samples we can calculate the statistics and infere properties about a population. This inferences obviously came with some uncertainty, depending on the properties of the sample and specially the sample size.
When we talk about confidence intervals, we use the statistic of the sample (in this case, the mean) to estimate a range of values it is expected to find the true mean of the population. The width of this interval depends on the sample standard deviation and the sample size.
The value of the confidence interval (95%, 99%, etc) represent the probabilty that the true mean is within this interval.
