A civil engineer tested concrete samples to investigate the difference in strength, in newtons per square millimeter (N/mm2), between concrete hardened for 21 days and concrete hardened for 28 days. The engineer measured the strength from each sample, calculated the difference in the mean strength between the samples, and then constructed the 95 percent confidence interval, (2.9,3.1), for the difference in mean strengths.

Assuming all conditions for inference were met, which of the following is a correct interpretation of the 95 percent confidence level?

a) In repeated samples of the same size, approximately 95 percent of the samples will yield the interval 2.9 N/mm^2 to 3.1 N/mm^2.

b) In repeated samples of the same size, approximately 95 percent of the sample means will fall between 2.9 N/mm^2 and 3.1 N/mm^2
c)In repeated samples of the same size, approximately 95 percent of the intervals constructed from the samples will extend from 2.9 N/mm^2 to 3.1 N/mm^2.

d)In repeated samples of the same size, approximately 95 percent of the intervals constructed from the samples will capture the population difference in means.

e) In repeated samples of the same size, approximately 95 percent of the intervals constructed from the samples will capture the sample difference in means.

You and three friends will be going out to eat at your favorite restaurant! each of you will order three items of your choice. you will also need to leave a tip. if you split the bill evenly among all four of you, how much will each person need to contribute? locate a menu for your favorite restaurant and pick three items for yourself and each friend. list the restaurant name, items, and prices in a table like the one below. in the column labeled subtotal, determine the cost of each person’s order. the customary tip is 20% of the total bill. in the column labeled tip, calculate the amount of tip each person should leave. in the column labeled total bill, determine the total of each person’s order, including the tip. restaurant name: names item 1 price item 2 price item 3 price subtotal tip total bill your name friend #1 friend #2 friend #3 part 2: questions answer the following questions, showing all work: what is the total cost of the entire bill (all four meals), including tip? write an expression using fractions to show how to determine the amount that each person will pay. then calculate each person's contributions showing all steps in long division. if each person paid an equal amount, who would save the most money? explain your reasoning using at least two complete sentences.

Fill in the missing exponents in each box and show how you found the answer. (4 points: 2 points for each correct answer with work shown) c. (9^4)^? =9^1 d.(5^? )^3=5^1 *question marks represent the boxes

Mr. jones determined that the equation y = 98 - 16/5 x could be used to predict his students' unit test scores, based on the number of days, x, a student was absent during the unit. what was the meaning of the y-intercept of the function? (by the way the 16/5 is a )