Order the numbers from least to greatest 7.8 7.88 7.78 7.87 7.77

Astudy claims that the mean age of online dating service users is 40 years. some researchers think this is not accurate and want to show that the mean age is not 40 years. identify the null hypothesis, h0, and the alternative hypothesis, ha, in terms of the parameter μ. select the correct answer below: h0: μ≥40; ha: μ< 40 h0: μ≤40; ha: μ> 40 h0: μ≠40; ha: μ=40 h0: μ=40; ha: μ≠40

Sound travels about 750 miles per hour. a) suppose it takes about 1.5 seconds to hear the echo. how far away is the canyon wall, in feet? for this i got 825 ft b) suppose you stand 1,925 feet from the canyon wall and sound the horn. how long will it take to hear the echo? (i'm stuck on this)

Which of the following statements is true? a. a 10o angle is congruent to a 10o angle. b. a triangle can only have two congruent angles. c. congruent angles always add up to 90o. d. a congruent angle is always 90o.