Answer:
Step-by-step explanation:
Given that n =30, x bar = 375 and sigma = 81
Normal distribution is assumed and population std dev is known
Hence z critical values can be used.
For 95% Z critical=1.96
Margin of error = 
Confidence interval = 375±29
=(346,404)
B) 99% confidence
Margin of error = 2.59*Std error =38
Confidence interval = 375±38
=(337, 413)
C) For 90%
Margin of error = 20
Std error = 20/1.645 = 12.158
Sample size
Atleast 44 people should be sample size.
Multiply 6 by $16.50 to get the total amount = $99
now to get the percentage discount : 99-90 (which is the difference) / 99 (original price of what it should have been )
and then multiply by 100 to get the percentage discount
Answer:
Step-by-step explanation
- Let x be the number of adults and y the number of kids
We can then write this two equations :
x+y= 33
15x+7y= 311
- let's solve the two eaquations
to do that we should combine them both in a way that help us get rid of one of the variables.
Let's multiply the first equation by -7 to get rid of y by adding it to thr second equation
-7x-7y= -231
now add both equations .
15x+7y-7x-7y=311-231
we get : 8x = 80
as you notice y is gone and we get a classic easy equation to solve
x= 80/8
= 10
so the number of adults is 10
let's go back to the first equation ( x+y= 33) and replace x with 10
10+y= 33
y= 33-10
=23
let's check using the second equation :
(10*15)+(23*7) = 311
that is true
so :
- the number of adults is 10
- the number of kids is 23
Answer:
(x , y) ----> (-x , y)
Step-by-step explanation:
(x , y) ----> (-x , y)
Example for 1. :
(-4,2) ---> (4,2)
Answer:
36
Step-by-step explanation:
(Top bottom plus bottom bottom )× height divided by 2
(4+6)*6÷2=36
