17 Calculate the standard error for the difference in means using the sample information given. n1=170, x¯1=76, s1=19.3 and n2=60, x¯2=99, s2=17.6 Round your answer to three decimal places. standard error =

Cumulative frequency Male Beagles 50- 45- 40- 35- 30- 25- 20- 15- 10- 5- 0- 19.5 22.5 25.5 28.5 31.5 34.5 Weight (in pounds) 55-

Use the expression in the accompanying discussion of sample size to find the size of each sample if you want to estimate the difference between proportions of men and women who own smartphones assume that you want 99% confidence that your area is no more than 0.045

What's the t= ? And the p-value?

In a city with three high schools, all the ninth graders took a Standardized Test, with these results: Number of ninth graders (Frequency) Mean Test Score High School Glenwood 82 262 Central 92 311 Lincoln 67 168 The city's PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was the average of 82, 92, and 67, whic incorrect. What is the mean score for all ninth graders in the city? Round to one decimal place 80.3. Of course, that is Mean of all ninth grader's scores *

ed in in the table 2. Find the mean, median, and mode for the following sample of scores: one person the sample 12. A sample One persoi 5 4 5 2 7 1 3 5 ust use the s found stribution nidpoint of students edian, you ates the highest quency. epresen-

Biologists studying horseshoe crabs want to estimate the percent of crabs in a certain area that are longer than 35 centimeters. The biologists will select a random sample of crabs to measure. Which of the following is the most appropriate method to use for such an estimate? A one-sample z-interval for a population proportion A A one-sample z-interval for a sample proportion B A two-sample z-interval for a population proportion C A two-sample z-interval for a difference between population proportions D A two-sample z-interval for a difference between sample proportions