Answer:
z-test.
Step-by-step explanation:
We want to perform an hypothesis test for a population mean.
In the case that the <u>standard deviation of the population is known</u> and the population distribution is normal, even if the sample is small, <u>we will use a z-test</u>.
The usual case is to not know the standard deviation of the population, in which case a t-test is adequate instead of a z-test, taking into account the degrees of freedom of the sample.
Answer:
x=4
Step-by-step explanation:
In order to solve for x, we must isolate x on one side of the equation.
x+3x+5=21
First, combine like terms. x and 3x are both terms with variables, and can be combined.
(x+3x) + 5=21
4x + 5=21
5 is being added to 4x. The inverse of addition is subtraction. Subtract 5 from both sides of the equation.
4x+5-5= 21-5
4x= 16
x is being multiplied by 4. The inverse of multiplication is division. Divide both sides by 4.
4x/4=16/4
x= 16/4
x=4
Let's check our solution. Plug 4 in for x and solve.
x+3x+5=21
4+3(4)+5=21
4+12+5=21
16+5=21
21=21
This solution checks out, so we know our answer is correct.
x is equal to 4, x=4.
9×10⁴ is 300 times greater than 3×10²
as, (9×10⁴)/(3×10²)=3× 10²
and the proper of writting powers in computer form is a×10^b
Answer:
4.5
Step-by-step explanation:
If 2/5 is blue, that means 3/5 is white. Now I convert it to a decimal: 0.6. That means 60% of the paint is white, so I can do 7.5*0.6 to find how much white paint was in there. Click thanks and Brainliest if it helped! Have an awesome day :D
