Answer:
A sample of 179 is needed.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 1.44.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
A previous study found that for an average family the variance is 1.69 gallon?
This means that 
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
Rounding up
A sample of 179 is needed.
Answer:
(ab - 6)(2ab + 5)
Step-by-step explanation:
Assuming you require the expression factorised.
2a²b² - 7ab - 30
Consider the factors of the product of the coefficient of the a²b² term and the constant term which sum to give the coefficient of the ab- term
product = 2 × - 30 = - 60 and sum = - 7
The factors are - 12 and + 5
Use these factors to split the ab- term
= 2a²b² - 12ab + 5ab - 30 ( factor the first/second and third/fourth terms )
= 2ab(ab - 6) + 5(ab - 6) ← factor out (ab - 6) from each term
= (ab - 6)(2ab + 5) ← in factored form
Answer in fraction form is 1/3
Answer in decimal form is 0.3333
Pick one answer only.
==========================================================
Explanation:
The sample space is the set of all possible outcomes. In this case, the outcomes consist of values between 1 and 6
S = sample space
S = {1,2,3,4,5,6}
There are 6 items here. Let B = 6.
We want to roll a number greater than 4, so the event space we're after is
E = {5,6}
which consists of 2 items. Let A = 2.
The probability we want is A/B = 2/6 = 1/3 = 0.3333
So if you go with the fraction option, then you'll type in 1/3
If you go with the decimal option, then you'll type in 0.3333
Answer:
Below.
Step-by-step explanation:
30 kg 500g + 28kg 700g
= 58kg + 1200g
= 59kg 200g.
Difference
= 30 kg 500g - 28kg 700g
= 2kg + 500 - 700
= 2kg - 200g
= 1kg 800g.
