1. The local school district is comparing two methods for teaching mathematics to
third-grade children. One class of n1= 20 students is being taught by method A
and another class of n2= 20 is being taught by method B. At the end of the
school year, all of the students take a standardized math achievement test. The
scores for the students taught by method A produced a mean of X1 = 75 with sx1
= 9.73, and the students taught by method B had a mean of X2 = 87 with sx2 =
10.26. Do these data indicate a significant difference between methods at the .05
alpha level?
a. Identify the independent variables and the dependent variables.
b. Step 1: State the hypotheses.
c. Step 2: Set the criteria for a decision.
d. Step 3: Compute statistic.

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Find the cosine function that is represented in the graph.

An annual marathon covers a route that has a distance of approximately 26 miles. winning times for this marathon are all over 2 hours. the following data are the minutes over 2 hours for the winning male runners over two periods of 20 years each. earlier period 14 12 15 22 13 10 19 13 9 14 20 18 16 20 23 12 18 17 6 13 recent period 7 11 7 14 8 9 11 14 8 7 9 8 7 9 9 9 9 8 10 8 (a) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the earlier period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks. for more details, view how to split a stem.) minutes beyond 2 hours earlier period 0 1 2 (b) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the recent period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks.) minutes beyond 2 hours recent period (c) compare the two distributions. how many times under 15 minutes are in each distribution