The number of students that belong to the dance company at each of several rando
ID: 3262029 • Letter: T
Question
The number of students that belong to the dance company at each of several randomly selected small universities is shown below. We want to estimate the true population mean size of a university dance company with 99% confidence. 21 47 32 25 26 27 32 35 40 22 26 28 35 30 26 29 28 30 28 What's the margin of error for this interval, correct to 3 decimals? _______________ For a normally distributed set of data, half of the data is below the mean. This is a multiple answer. Check all that apply for full credit. It is symmetric. The median is larger than the mean. It has a peak about the mean. The spread of the curve is proportional to its standard deviation. The Graduate Record Examinations are widely used to help predict the performance of applicants to graduate schools. The range of possible scores on the capital of GRE is 200 to 900. The psychology department at a university finds that the scores of its applicants on the quantitative GRE are approximately normal with mean = 544 and population standard deviation = 103. Use the z-table to find the probability of applicants who score is between 500 and 700. (Please write your answer as a decimal. The testing system is not able to recognize a % sign. So if you have 1.23% then this should be written as 0123 which is the decimal equivalent.) A 95% confidence interval for the mean mu of a population is computed from a random sample and found to be between (6, 12). We may conclude that: There is a 95% probability that the population mean is between 6 and 12. There is a 95% probability that the true population mean is 9 and a 95% chance that the true margin of error is 3. If we took many, many additional random samples and computed a 95% confidence interval for the true population mean from each of these samples, approximately 95% of these intervals would contain the population mean.Explanation / Answer
26)
for (n-1=18) degree of freedom and 99% CI ; t=2.8784
therefore margin of error =t*Std error =4.078
27)
correct options are A,C,D
28)P(500<X<700)=P((500-544)/103<Z<(700-544)/103)=P(-0.4272<Z<1.5146)=0.9351-0.3346=0.6004
29)
option C should be right ; also optioon D is not visible ; please revert on this
X 21 47 32 25 26 27 32 35 40 22 26 28 35 30 26 29 28 30 28 mean(X) 29.842 std deviation(S) 6.176 std error =S/(n)1/2 1.417