Every confidence interval has associated z value. As confidence interval increases so do the z value associated with it.
The confidence interval can be calculated using following formula:

Where

is the mean value, z is the associated z value, s is the standard deviation and n is the number of samples.
We know that standard deviation is simply a square root of variance:

The confidence interval of 95% has associated z value of <span>1.960.
</span>Now we can calculate the confidence interval for our income:
Answer:
see below
Step-by-step explanation:
1.
m = (y2-y1)/(x2-x1)
= (90-80)/(0-1)
= 10/-1
=-10
The slope is -10 ft/s
This means the height decreases 10 ft for every second that passes
This is not proportional because it has to go through the point (0,0)
4.
m = (y2-y1)/(x2-x1)
= (1000-0)/(3-0)
= 1000/3
=1000/3
The slope is $1000/3
This means the 1000 dollars is sold every 3 days
This is proportional because it goes through the point (0,0) and has a constant slope
There are 11 trains containing giraffes and 7 trains containing rabbits.
<h3>
Equation</h3>
An equation is an expression used to show the relationship between two or more numbers and variables.
Let x represent the number of train with giraffes and y represent the number of train with rabbits.
Hence:
25x = 40y
25x - 40y = 0 (1)
Also:
25x + 40y > 500 (2)
From both equations:
A possible solution is x = 11, y = 7
There are 11 trains containing giraffes and 7 trains containing rabbits.
Find out more on Equation at: brainly.com/question/22688504
Answer:
D. 14.32
Step-by-step explanation:
The formula for standard deviation is:

The mean μ is 33.
The (x minus μ) squared are 361, 49, 49, 361 respectively.
So that the SD = 
Well, since 3/15 can be simplified to 1/5 by dividing the top and the bottom by 3, you would just need to find the decimal of 1/5 which is much more commonly recognized. it's .2 (becasue 1/10 would be .1 and 1/5=2/10 so .1x2=.2)