g Jack is polling New Yorkers to determine what proportion of them want to legalize recreational marijuana. How many New Yorkers should the sample to ens

1006

Step-by-step explanation:

Take proportion, p = 62%

n = (Z² * pq) / M.E²

Margin error = 0.03

p = 62% = 0.62

q = 1 - p = 1 - 0.62 = 0.38

Zcritical at 95% = 1.96

n = (1.96² * (0.62*0.38)) / 0.03²

n = 0.90508096 / 0.0009

n = 1005.6455

n = 1006

Sample size = 1006

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

equation image indicator

x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

equation image indicator

x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

equation image indicator

x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

for me what is finding a good play list and going out because i can not lay down and relax so i usually go to a coffee shop. i also use the gum trick and this actually works. another advice is highlighting subjects it really does me remember certain things

step-by-step explanation: