at the dog show, there are 4 times as many boxers as spaniels, if there are a total of 30 dogs, how many dogs are spaniels?
2 answers:
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Answer:
1) A. H0: p = 0.30
HA: p not equal to 0.30
2) A. The Independence Assumption is met.
C. The Randomization Condition is met.
D. The Success/Failure Condition is met.
3) Test statistic z = 2.089
P-value = 0.0367
4) C. Reject H0. There is sufficient evidence to suggest that the percentage of bills paid by medical insurance has changed.
Step-by-step explanation:
1) This is a hypothesis test for a proportion.
The claim is that there is a significant change in the percent of bills being paid by medical insurance.
As we are looking for evidence of a difference, no matter if it is higher or lower than the null hypothesis proportion, the alternative hypothesis is defined by a unequal sign.
Then, the null and alternative hypothesis are:
2) Cheking the conditions:
The independence assumption and the randomization condition are met as the bills were selected randomly from the population.
The 10% condition can not be checked, as we do not know the size of the population.
The success/failure condition is met as the products np and n(1-p) are bigger than 10 (the number of successes and failures are both bigger than 10).
3) The significance level is assumed to be 0.05.
The sample has a size n=9260.
The sample proportion is p=0.31.
The standard error of the proportion is:
Then, we can calculate the z-statistic as:
This test is a two-tailed test, so the P-value for this test is calculated as:
As the P-value (0.0184) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that there is a significant change in the percent of bills being paid by medical insurance.
Answer:
Janice and Karen could do in 1 day:
- <u>20% of the job</u>.
Step-by-step explanation:
To identify how much of the job could janice and caren do in 1 day, first, we must find how much of the job make just 1 person at the same rate:
If three persons make a job in 3 1/3 days, 1 person make the job in x:
- 3 persons ⇒ 3 1/3 days or 10/3 days
- 1 person ⇒ x
Then:
(we cancel the unit "persons")
- x = 10 days
Just a person would need 10 days to complete a job, now, we're gonna divide this value in 2 to obtain the time that need two persons to complete a job:
- Time to complete a job between 2 persons =
- Time to complete a job between 2 persons = 5 days
How two persons need 5 days to complete a job (in this case, the two persons are Janice and Karen), we can make a simple rule of three to obtain the percentage made in 1 day:
- 5 days ⇒ 100% of a job
- 1 day ⇒ x
Then:
(you can use the % if you want, the result is the same)
As you can see, <u><em>Janice and Karen just in a day could do 20% of the job</em></u>.