Answer:
1 - 1/10
Step-by-step explanation:
As strange as it may seem, the easiest way to answer this question is to calculate the probability of selecting an elephant first and then to subtract this probability from 1:
Adding up the Numbers of animals, we get 12+4+3+11, or 30. The probability of selecting an elephant is thus 3/30, or 1/10.
Thus, the probability of NOT selecting an elephant is 1 - 1/10 (Answer A).
Answer:
a. We reject the null hypothesis at the significance level of 0.05
b. The p-value is zero for practical applications
c. (-0.0225, -0.0375)
Step-by-step explanation:
Let the bottles from machine 1 be the first population and the bottles from machine 2 be the second population.
Then we have 
, 
, 
and 
, 
, 
. The pooled estimate is given by
a. We want to test 
vs 
(two-tailed alternative).
The test statistic is 
and the observed value is 
. T has a Student's t distribution with 20 + 25 - 2 = 43 df.
The rejection region is given by RR = {t | t < -2.0167 or t > 2.0167} where -2.0167 and 2.0167 are the 2.5th and 97.5th quantiles of the Student's t distribution with 43 df respectively. Because the observed value 
falls inside RR, we reject the null hypothesis at the significance level of 0.05
b. The p-value for this test is given by 
0 (4.359564e-10) because we have a two-tailed alternative. Here T has a t distribution with 43 df.
c. The 95% confidence interval for the true mean difference is given by (if the samples are independent)
, i.e.,
where 
is the 2.5th quantile of the t distribution with (25+20-2) = 43 degrees of freedom. So
, i.e.,
(-0.0225, -0.0375)
Answer:
yes x=1
Step-by-step explanation:
x
Answer: 20-2x/-4
Step-by-step explanation:
To actually solve for y as a number, you need two equations.
For this case move the 2x to the other side, making the equation -4y=20-2x.
Then divide by -4 on each side making the equation y=20-2x/-4.
