Research suggests that the pressure of being timed may interfere with performance on tests that involve mathematical problems. a fictional study was conducted with 30 sixth graders. first, the sixth graders were given a math test that contained 50 problems and were told that they had only one hour to complete it (timed condition). the same sixth graders were later given a math test that contained 50 problems and were told that they could have as much time, as needed, to complete the test (unlimited time condition). the total number of correct answers for each sixth grader was then calculated for each condition. then, for each student, the difference between the two scores (timed − untimed) was calculated. the researchers hypothesized that the sixth graders would get fewer correct answers when they took the test with a time limit than when they had unlimited time. if μ1and μ2represent the number of correct answers during the timed condition and the unlimited time condition, respectively, and let μd be the mean of the differences in the number of correct answers (timed − untimed) of all sixth graders. which of the following are the appropriate null and alternative hypotheses? a. h0: μd = 0 ha: μd > 0 b. b. h0: μd = 0 ha: μd < 0 c. c. h0: μd < 0 ha: μd = 0 d. d. h0: μ1 − μ2 = 0 ha: μ1 − μ2 < 0

answer: check all that apply, where the options?

step-by-step explanation:

so then what are you asking?

step-by-step explanation:

18.75 gallons

step-by-step explanation:

ratios represent a pattern or relationship that can be scaled.

equivalent ratios are pairs of ratios that represent the same relationship between quantities, and can be generated by multiplying or dividing both quantities in the ratio by the same factor.

in this lesson, students will use double number lines and ratio reasoning to solve ratio problems. by partitioning double number lines into proportionate intervals, students will build an understanding of equivalent ratio relationships as those that are generated by multiplying or dividing two related quantities by the same number. this lesson will build upon students' prior understanding of multiplicative comparisons, number line reasoning and equivalent fractions (while highlighting the difference between equivalent fractions and equivalent ratios); and will build toward future work in this unit on building ratio tables, and work in future grades in proportionality, scaling, and expressing and graphing linear functions.

step-by-step explanation:

ratios represent a pattern or relationship that can be scaled.

equivalent ratios are pairs of ratios that represent the same relationship between quantities, and can be generated by multiplying or dividing both quantities in the ratio by the same factor.

in this lesson, students will use double number lines and ratio reasoning to solve ratio problems. by partitioning double number lines into proportionate intervals, students will build an understanding of equivalent ratio relationships as those that are generated by multiplying or dividing two related quantities by the same number. this lesson will build upon students' prior understanding of multiplicative comparisons, number line reasoning and equivalent fractions (while highlighting the difference between equivalent fractions and equivalent ratios); and will build toward future work in this unit on building ratio tables, and work in future grades in proportionality, scaling, and expressing and graphing linear functions.