The composition of the earth's atmosphere may have changed over time. to try to discover the nature of the atmosphere long ago, we can examine the gas in bubbles inside ancient amber. amber is tree resin that has hardened and been trapped in rocks. the gas in bubbles within amber should be a sample of the atmosphere at the time the amber was formed. measurements on specimens of amber from the late cretaceous era (75 to 95 million years ago) give these percents of nitrogen: 63.4 65.0 64.4 63.3 54.8 64.5 60.8 49.1 51.0 assume (this is not yet agreed on by experts) that these observations are an srs from the late cretaceous atmosphere. use a 95% confidence interval to estimate the mean percent of nitrogen in ancient air. % to %

hello, there is a new name in town and that's the human spider!

answer: d.) the total number of protons and neutrons is 15

merry christmas!

~

your friendly neighborhood human spider! .

part a: triangles gcb and epb

part b. sides cg and rp are parallel by definition of parallelogram.

angles cgb and e are congruent by being alternate interior angles of parallel lines cut by a transversal. angles gbc and ebp are congruent because they are vertical angles. by aa similarity, the triangles are similar.

part c. since the triangles are similar, the ratios of the lengths of corresponding sides are equal.

calculation of be:

gb/be = cb/bp

(400 ft)/be = 300/200

(400 ft)/be = 3/2

3be = 2 * 400 ft

3be = 800 ft

be = 800/3 ft

calculation of pe:

gc/pe = cb/bp

(350 ft)/pe = 300/200

(350 ft)/pe = 3/2

3pe = 2 * 350 ft

3pe = 700 ft

pe = 700/3 ft

8p+(-9)

(-9)3p+5p and you can swith em around