Answer:
The standard error of the proportion is 0.112.
Step-by-step explanation:
The standard error of a proportion is given by the following formula:
In which p is the probability of a success and n is the length of the sample.
In this problem
A success is a student defining themselves regular dietary supplement users. Our of 3000 students, 1500 do. So .
We take a sample of 20 of them, so .
So
Answer:
625 minutes
Step-by-step explanation:
Given that:
Time taken to tie 4 ribbons = 10 minutes
Number of ribbons to be tied = 250
To find:
Time taken to tie 250 ribbons.
Solution:
First of all, we need to find the time taken to tie one ribbon.
And then we can multiply it with 250 to find the time taken to tie all the 250 ribbons.
For finding the time to tie one ribbon, we need to divide the time taken to tie 4 ribbons with 4.
Time taken to tie 1 ribbon = minutes
Time taken to tie 250 ribbons = 2.5 250 = <em>625 minutes</em>
(a)
The sample space is a set whose elements are all the possible outcomes for the experiment. Since we will extract one of the months of the years, the sample space is the set composed by all the 12 months:
(b)
An event is a subset of the sample space. Events are often defined by their properties. In this example, the event E is the subset of the sample space defined as
So, we have
(c)
If all outcomes have equal probability, then the probability of an event is the ratio bewteen its cardinality, and the cardinality of the whole sample space:
In words, since there are three months beginning with J out of 12 months, we have a probability of 3 over 12 to pick a month starting with J, which simplifies to 1 over 4.