Answer:
x = 61 degrees
Step-by-step explanation:
The triangle on the right is isosceles and the base angles are congruent
the sum of the inner angles of a triangle is 180 degrees
2 * 74 + y = 180
148 + y = 180
y = 32 degrees
the total angle is 90 degrees
so we have that
90 - 32 = 58 degrees
Also the left triangle is isosceles, so we have
2x + 58 = 180
2x = 122
x = 61 degrees
Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
For this problem, we have that:
95% confidence level
So , z is the value of Z that has a pvalue of , so .
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
One way in which to approach this problem would be to treat it as an equation of ratios and to cross multiply:
<span>[(4x + 15) / 5x)] = 1/2 could be written as:
4x + 15 1
----------- = ---
5x 2
Then 8x + 30 = 5x
3x = -30, and so x = -10 (answer). Be certain to check this answer through substitution!
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John Frank Stevens, William C Gorgas and George Washington Goethals 1914 (opened)The building of the 50-mile-long Panama Canal was a collosal project, joining together the Pacific and Atlantic oceans by digging away 240 million metric tons of earth through the Isthmus of Panama. Almost as big a project was sanitising the area around the canal, which was mosquito infested and home to serious diseases like Malaria and Yellow Fever.
<span> In 1907 President Roosevelt appointed George Washington Goethals, a military engineer, as head of the project, and under his leadership the canal was finally completed in 1914, two years ahead of the 1916 target. Of benefit to the whole world, the achievement of the Panama Canal signalled American dominance in project management and engineering like no other project of the day.</span>