Answer:
Step-by-step explanation:
Hello!
In stratified sampling, the researcher separates the population into subgroups according to the criteria established for his experiment. These subgroups will be made up of homogeneous observation units in terms of the characteristics of interest. In this case, each of the people who make up the groups will have only one of the two possible opinions (support, do not support) but not both.
When this type of sampling is performed, it is the researcher who decides what sample size you want to take, depending on various economic factors, availability of materials, access to experimental units (for example, if they are endangered animals, that is, finite populations , you cannot take very large sample sizes)
You can perform a proportionate stratified sampling and take a proportion of people who answered "yes" and a proportion of people who answered "no."
In this type of sampling, when taking a given proportion of each population, it is easier to extrapolate the results obtained to the populations. Then, if for example you must take a sample of size n = 20 where both strata correspond to half, that is to say that the stratum corresponding to "yes" will be 10 people and the stratum corresponding to "no" will be ten people.
I hope this helps!
<span>If Charles leaves the marina and sails his boat 10° west of north for 1.5h at 18km/h, then makes a right turn towards 60° east of north for 1.2h at 20km/h, he is 42 km from his starting point.</span>
Answer:
The probability is 0.2650
Step-by-step explanation:
Let's start assuming that men and women come in at the same rate.
Let's define the following random variables :
X : ''Number of people that enter a drugstore''
M : ''Number of men that enter a drugstore''
W : ''Number of women that enter a drugstore''
The number of people will be the number of men plus the number of women
⇒
X = M + W
We are also assuming that M and W are independent random variables.
X ~ Po (10)
M ~ Po (λ1)
W ~ Po (λ2)
λ1 = λ2 because we assumed that men and women come in at the same rate.
λ1 = λ2 = λ
λ1 + λ2 = λ + λ ⇒ 2λ = 10 ⇒ λ = 5
M ~ Po (5)
W ~ Po (5)
Because X is the sum of two independent Poisson random variables.
We are looking for :
Because we assume independence.
because is a Poisson random variable with λ = 5
Answer:
14.4 lb
Step-by-step explanation:
In a see-saw in equilibrium, the torque generated by one side needs to be the same generated in the other side. The torque is calculated by the product between the mass and the distance to the center of the see-saw.
The torque generated by the child is:
T1 = 60 * 3 = 180 lb*feet
So, the torque generated by the weight needs to be higher than T1 in order to lift the child.
The lowest mass is calculated when the mass is in the maximum distance, that is, 12.5 feet from the center.
So, we have that:
T2 = 180 = mass * 12.5
mass = 180/12.5 = 14.4 lb
So the lowest weight is 14.4 lb
Answer:
t=100
Step-by-step explanation:
The easiest way is to graph them—otherwise, set each equation equal to each other:
.1x=.05x +5
