There is a proposal before congress to build a so-called fourth-generation nuclear reactor at the idaho national laboratory. government officials want to estimate the true proportion of citizens in the state who support building the reactor. the most recent survey on idaho public opinion about building nuclear reactors showed 40% in favor. if the government officials want a margin of error of 4% and a confidence level of 90%, how many voters will they need to survey?

406

Step-by-step explanation:

Data provided in the question:

Margin of error, E = 4% = 0.04

Probability of people in favor, p = 40% = 0.4

Confidence level = 90%

Now,

For 90% confidence level, the z value = 1.645

let n be the required sample size

Thus,

n = p(1 - p)( z ÷ E)²

or

n = 0.4 × (1 - 0.4)( 1.645 ÷ 0.04 )²

or

n = 0.4 × 0.6 × 1691.265625

or

n = 405.90 ≈ 406

answer:

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

explanation:

service only with 20% tip  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

in the opening of the question the word 'service' is associated only with the pretax value.

the closing part of the question asks: how much did she pay for the  

service

−−−−−−  

so technically the answer is  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

however, the intention of the question provider may have been that your answer is to be  

$

87.12

(

1

+

8

100

)

=

$

94.09

to 2 decimal places.

'

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

tony b

mar 21, 2017

answer:

trying to explain it another way

explanation:

service charge  

.

→

$

72.60

20% tip  

20

100

×

$

72.60

=

$

14.52

−−−−−−  

←

add

$

87.12

tax  

8

100

×

$

87.12

=

$

6.97

−−−−−  

←

add

$

94.09

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