Answer:
the length is 40m
Step-by-step explanation:
Part a)
The simple random sample of size n=36 is obtained from a population with

and

The sampling distribution of the sample means has a mean that is equal to mean of the population the sample has been drawn from.
Therefore the sampling distribution has a mean of

The standard error of the means becomes the standard deviation of the sampling distribution.

Part b) We want to find

We need to convert to z-score.

Part c)
We want to find

We convert to z-score and use the normal distribution table to find the corresponding area.

Part d)
We want to find :

We convert to z-scores and again use the standard normal distribution table.

Answer with explanation:
To test the Significance of the population which is Normally Distributed we will use the following Formula Called Z test


→p(Probability) Value when ,z=3.756 is equal to= 0.99992=0.9999
⇒Significance Level (α)=0.01
We will do Hypothesis testing to check whether population mean is different from 25 at the alpha equals 0.01 level of significance.
→0.9999 > 0.01
→p value > α
With a z value of 3.75, it is only 3.75% chance that ,mean will be different from 25.
So,we conclude that results are not significant.So,at 0.01 level of significance population mean will not be different from 25.
Answer:
1 in 30
Step-by-step explanation:
1 in 6 chance Mary picks the red marble in the first place. After this there is a 1 in 5 chance her sister picks the blue one. 5 multiplied by 6 is 30.
Answer:
9A^2 - 16B^2.
Step-by-step explanation:
(3A+4B)(3A-4B) = 9A^2 + 12AB - 12AB - 16B^2 = 9A^2 - 16B^2.
Hope this helps!