Answer: 195
Step-by-step explanation:
Cost per student = $4
Total number who attended = n
The cost of the total of student who attended will be cost per student multiplied by the total number of students, that is
Total cos = 4n
Since, they are to pay $140 , for publicity, then the total cost becomes
T = 4n - 140
From the last statement
4n - 140 ≥ 640
4n ≥ 640 + 140
4n ≥780
n ≥ 780/4
n ≥ 195
That means at least 195 students must attend if the science club is to earn at least $ 640
Answer: 24:34
Step-by-step explanation:
If you multiply the ratio by 2, for example, it will still be equal.
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:
28
Step-by-step explanation:
In paralellograms, the lengths of the parallel sides are equal to each other
As seen in the figure, the side that is parallel to the side that is represented with x has a length of 28 units, so the value of x is also equal to 28