Answer: z-test for population mean.
Step-by-step explanation:
Given : purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the average daily revenue was $675 with a standard deviation of $75.
So the null hypothesis and alternative hypothesis will be :-
It means the test will be for population mean.
We assume that this is normally distributed.
We know that we use t-test for sample size less than 30 and z-test for sample size greater than 30 .
Since the sample size is 30, so the test use here is z-test for population mean.
N = 15
24÷2=12+3=15
........
check
15 -3 = 12
12 × 2 = 24
Answer:
- <em>After 1 minute, the population in a colony at 20ºC will be greater than the population in a colony at 30ºC.</em>
Explanation:
The specific question is added on the comments section: <em>After 1 minute, will the population be greater in a colony at 20ºC or 30ºC? Explain</em>
<h2><em>Solution</em></h2>
<u><em>How will the colonies compare in size? </em></u>
To answer this you can either evaluate each polynomial at the corresponding time and then compare or you can subtract the polynomials and then evaluate the resulting polynomial.
I choose the second opion:
20ºC 30ºC
↓ ↓
- <em> t² + 4t + 4 - (t² + 3t + 4 ) = t² - t² + 4t - 3t + 4 - 4 = t</em>
The difference is t (remember that this is number of bacteria).
Evaluate when the time is 1 minute.
In the polynomials, t is in seconds. Then, convert 1 minute to seconds:
Then, t = 60 bacteria is the difference.
Thus, the colony has 60 more bacteria when the temperature is 20ºC than when the temperature is 30ºC.
In fact, since t is always greater than 0, the colony at 20ºC will always have more bacteria than the colony at 30ºC.
The answer is A) -23
A is a 1x3 Matrix while B is 3x1 Matrix. Since A has the same number of rows as that of the number of columns of B, they can be multiplied. A has 1 row and B has 1 column. So, their products is a 1x1 Matrix.
Simply, the operation is:
(3)(-1) + (-2)(4) +(6)(-2) = -23
I believe your answer is A- true. Hope this helps!!
-K <3