The formula for the confidence interval is given by

Sample mean + z*[σ/√n], and
Sample mean - z*[σ/√n]

We have:
Sample mean = 23.95
n = 40
σ = 2.55
z* for 99% confidence = 2.58

Substitute these values into the formula, we have

23.95 + (2.58)(2.55÷√40) = 24.99
23.95 - (2.58)(2.55÷√40) = 22.91

So the lower interval is 22.91 and the highest interval is 24.99

5 0

3 years ago

PLEASE HELP ASAP!!!!

OleMash [197]

Answer:

y = -2x + 8

Step-by-step explanation:

The point slope form of an equation is written as

y = mx + c ...............(i)

Where m is the slope and c is the constant

Now we Know that the equation is

y + 2 = -2(x-5)

and the given points are

m= -2

x = 5

and y= -2

Putting these values in equation (i) to find the value of c

y = mx + c

it becomes

-2 = -2(5) + c

-2 = -10 + c

Adding 10 on both sides

-2 + 10 = -10 + 10 + c

8 = c

or c=8

Now we have the values of m and c

where m= -2 and c = 8

Point slope form of an equation is

y = mx + c

putting the values of m and c to get equation in slope intercept form is

y = (-2)x + 8

y = -2x + 8

Other method:

The given point slope form is

y + 2 = -2(x-5)

We have to change it in y= mx + c form

so solving it

y + 2 = -2x + 10

Subtracting 2 from both sides

y + 2 -2 = -2x + 10 -2

y = -2x + 8

which is same is

y=mx + c

so the required equation is

y = -2x + 8

7 0

3 years ago