!!!!!!!I NEED HELP WITH THESE PROBLEMS. THANK YOU!!!!!

you did 150 J of work lifting a 120 N backpack. how much did the backpack weigh in pounds?(hint:there are 4.448 N in one pound)

a_sh-v [17]

If the backpack weighs 120 N, then the equivalent
weight in pounds is about 26.98 .

All that business about lifting and joules of work is
completely irrelevant to this question.

3 0

3 years ago

g In a certain rural county, a public health researcher spoke with 111 residents 65-years or older, and 28 of them had obtained

Marat540 [252]

Answer:

95% confidence interval for the percent of the 65-plus population that were getting the flu shot is [0.169 , 0.331].

Step-by-step explanation:

We are given that in a certain rural county, a public health researcher spoke with 111 residents 65-years or older, and 28 of them had obtained a flu shot.

Firstly, the Pivotal quantity for 95% confidence interval for the population proportion is given by;

P.Q. = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = sample proportion of residents 65-years or older who had obtained a flu shot = $\frac{28}{111}$ = 0.25

n = sample of residents 65-years or older = 111

p = population proportion of residents who were getting the flu shot

Here for constructing 95% confidence interval we have used One-sample z test for proportions.

So, 95% confidence interval for the population proportion, p is ;

P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5% level

of significance are -1.96 & 1.96}

P(-1.96 < $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < 1.96) = 0.95

P( $-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < ${\hat p-p}$ < $1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.95

P( $\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ < p < $\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ) = 0.95

95% confidence interval for p = [ $\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ , $\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ]

= [ $0.25-1.96 \times {\sqrt{\frac{0.25(1-0.25)}{111} } }$ , $0.25+1.96 \times {\sqrt{\frac{0.25(1-0.25)}{111} } }$ ]

= [0.169 , 0.331]

Therefore, 95% confidence interval for the percent of the 65-plus population that were getting the flu shot is [0.169 , 0.331].

7 0

3 years ago

Help me with these 2 questions please

pishuonlain [190]

Answer:

I believe for the second one it's B, then for the third one it's D

Step-by-step explanation:

Oh also be careful w ur lunch # showing

4 0

2 years ago

How to work this out ?

Free_Kalibri [48]

Answer:

The solution is (-3, -2).

Step-by-step explanation:

Please note that if you simply add these 2 equations together, 9x - 9x = 0, and you are then left with -5y = 10. Thus, y = -2. Subbing -2 for y in the first equation, we get 9x - 8(-2) = -11, or 9x + 16 = -11.

Subtracting 16 from both sides, we get 9x = -27, so that x = -3.

The solution is (-3, -2).

6 0

2 years ago

How do you simplify this

Gala2k [10]

15 + 1 because you are using apsolute value so that negative 1 becomes a positive

8 0

3 years ago