7 . Sampling distribution of the difference between two means A statistician is interested in the effectiveness of a weight-loss
1 answer:
Answer:
0.229
Step-by-step explanation:
Given that the difference between the two sample means follows anormal distribution with a mean of11.00 and standard deviation equal to1.4387
A statistician is interested in the effectiveness of a weight-loss supplement. She randomly selects two independent samples. Individuals in the first sample of size n1 = 24 take the weight-loss supplement. Individuals in the second sample of size n2 = 21 take a placebo. Individuals in both samples follow identical exercise and diet programs. At the end of the study, the statistician measures the weight loss (in percent) of each participant.
We find that mean difference actual = 13-2 = 11
Probability that difference >12 =P(Z>)
=P(Z>0.742)=.0.229
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Answer:
A) The population of this survey is the registered voters in the city of Raleigh.
B) 9500
C) 200
D) 0.325
E) 3088
Step-by-step explanation:
A) The population of this survey is the registered voters in the city of Raleigh.
B) Population size can be defined as the total number of individuals in a population. Here the total number of individuals are the registered voters in the city. Therefore the size of the population is 9500.
c) Sample size is defined as the number of individual samples in a statistical test. Here the sample size is the 200 randomly selected registered voters. It is denoted as "n".
d) The sample statistic for the proportion of voters surveyed who said they'd vote for Brown would be:
p' = voters for brown / sample size
The sample statistic for the proportion of voters surveyed who said they'd vote for Brown is 0.325
E) The expected number of voters for Brown based on the sample:
0.325 * 9500 = 3087.5
Approximately 3088
The expected number of voters for Brown based on the sample might be 3088 voters.