Can someone please help me on this I’ll give brainliest

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

The function f(x)=−2(0.25)x+1 is shown. Select from the drop-down menus to correctly describe the end behavior of f(x).

Viktor [21]

Answer:

Q1

cos 59° = x/16

x = 16 cos 59°

x = 8.24

Q2

BC is given 23 mi

Maybe AB is needed

AB = √34² + 23² = 41 (rounded)

Q3

BC² = AB² - AC²

BC = √(37² - 12²) = 35

Q4

Let the angle is x

cos x = 19/20

x = arccos (19/20)

x = 18.2° (rounded)

Q5

See attached

Added point D and segments AD and DC to help with calculation

BC² = BD² + DC² = (AB + AD)² + DC²

Find the length of added red segments

AD = AC cos 65° = 14 cos 65° = 5.9

DC = AC sin 65° = 14 sin 65° = 12.7

Now we can find the value of BC

BC² = (19 + 5.9)² + 12.7²

BC = √781.3

BC = 28.0 yd

All calculations are rounded

6 0

3 years ago

The table below shows the relative frequencies of the color of cars bought last month by males and females. Which percentage rep

frozen [14]

The first thing we must do for this case is to observe the highest relative frequency of the table in the total column.
For the white car we have:
Male = 0.11
Female = 0.20
Total = 0.31
The percentage is given by:
(0.31) * (100) = 31%
Answer:
The percentage that represents the car bought most often is:
31%

5 0

4 years ago

Jimmy threw a baseball in the air from the roof of his house. The path followed by the baseball can be modeled by the function f

erastovalidia [21]

Answer:

Step-by-step explanation:

The first part of A is easy. Look at the quadratic function, and the constant, the very last number with no t stuck to it represents the height from which the object in question was originally launched. Our constant is 40, so the height of the roof from which the baseball was thrown is 40 feet. Part 2 of A is not quite as simple because it requires factoring using the quadratic formula.Before we do that, let's make our numbers a bit more manageable, shall we? Let's factor out a -8 to get

$f(t) = -(t^2-6t-5)$ and a = 1, b = -6, c = -5.

Filling in the quadratic formula now looks like this:

$t=\frac{6+-\sqrt{6^2-4(1)(-5)} }{2(1)}$ and

$t=\frac{6+-\sqrt{36+40} }{2}$ and

$t=\frac{6+-\sqrt{56} }{2}$ so the 2 solutions are

$t=\frac{6+\sqrt{56} }{2}=6.74sec$ and

$t=\frac{6-\sqrt{56} }{2}=-.742sec$ and since we know time can NEVER be negative, the time it takes for the baseball to hit the ground from a height of 40 feet is 6.74 seconds. Onto part B.

In order to determine exactly how high the baseball did go, we have to find the vertex of the function. We do this by completing the square and getting the function into vertex, or work, form. Begin by setting the quadratic equal to 0, moving over the constant, and then factoring out the leading coefficient. The rule for completing the square are kinda picky in that you have to have a 1 as the leading coefficient, and righ now ours is a -8. So following the rules I stated above:

$-8(t^2-6t)=-40$ Next is the take half the linear term, square it, and then add it to both sides. Our linear term is a -6. Half of -6 is -3, and -3 squared is 9, so we add 9 into the parenthesis first:

$-8(t^2-6t+9)=-40+??$

Because this is an equation, we can't add 9 to one side without adding the equivalent to the other side. But, we cannot forget about that -8 sitting out front there, refusing to be ignored. We didn't just add in a 9, we actually added in a -8 times 9 which is -72. That's what goes on the right side in place of the ??.

$-8(t^2-6t+9)=-40-72$

The reason we complete the square is found on the left side of the equals sign. We have, in the process of completing the square, formed a perfect square binomial that will serve as the h in our vertex (h, k) where h is the number of seconds it takes for the baseball to reach its max height of k, whatever k is. That's what we have to find out. Putting the left side into its simplified perfect square binomial and adding the numbers on the right gives us:

$-8(t-3)^2=-112$

For the last step, add over the -112 and set it back equal to f(t):

$-8(t-3)^2+112=f(t)$ From that we determine that the vertex is (3, 112). The max height of this baseball was 112 feet...so no, it did not make it up to the height of 120 feet that Jimmy wanted for the baseball.

6 0

3 years ago

Which of the following expressions are equivalent (equal) to 3(2x - 7)

velikii [3]

Answer:

6x - 21

Step-by-step explanation:

3(2x - 7)

Use the Distribute Property of Multiplication by multiplying the number outside the parenthesis with the numbers inside.

3 × 2x = 6x

3 × -7 = -21

Combine:

6x - 21

Hope this helped.

3 0

3 years ago

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