难度超高的数学题，你能够hold住吗？  0 views

maly lo on 08 Nov 11Use for Questions 1 and 2 A grocery store takes a random sample of 200 customers. The average checkout time is 4 minutes with a standard deviation of two minutes. 1. The standard error of the mean is? 2. The 95% confidence level for the true average checkout time is? 3. A random sample of 244 observations has a mean of 10, a median of 12 and a mode of 33. The population deviation is known to equal 2.8. the 95.44% confidence interval for the population mean is? 4. The following random sample was collected: 22 33 44 6 The 80% confidence interval for the mean is? 5. A random sample of 200 people was taken. Sixty percent of the people favor President Obama. The 95% confidence interval for the true population of people who favor Obama is? 1. Define the null hypothesis. If the null hypothesis is rejected then? 2. The level of significance is the? 3. Type II error is committed when? 4. The level of significance in hypothesis testing is the probability of? 5. If n=16, mean = 75.76, s = 8.2466 H o: mean >80 H a: mean 1. If two large independent samples are taken from two populations, the sampling distribution of the difference between the two sample means can be determined how? 2. In my BMGT 230 class the fall semester is compared with my class 10 years ago. Please answer the following questions given: This FallTens Years Ago Mean 8085 Variance 10050 Sample 4060 a. the point estimate of the difference between means of the two populations is? b. the point estimate of the standard deviation of the difference between the means of the two populations is ? c. the 95% confidence interval for the difference between the two population means is? 1. Regression analysis was applied between sales in ($1000) and advertising(in $100), and the following regression function was obtained: Y = 61 +4.1X Based on this regression line, if advertising is $10,000, the point estimate for sales (in dollars) is what 2. How do we use a least squares reg