Answer:
The z-distribution should be used for this problem.
Step-by-step explanation:
The population distribution is assumed to be normal. Which distribution to use?
If we have the standard deviation for the sample, we use the t-distribution.
If we use the standard deviation for the population, we use the z-distribution.
There is a known standard deviation of 2.2 minutes.
This means that 2.2 is the population standard deviation, and thus, the z-distribution should be used for this problem.
Answer:
The top right option.
Step-by-step explanation:
2x + 4 = 3x - 10
-2x and +10 to both sides
14 = x
the answer is x = 14
Answer:
Since the calculated value of z= -1.496 does not fall in the critical region z < -1.645 we conclude that the new program is effective. We fail to reject the null hypothesis .
Step-by-step explanation:
The sample proportion is p2= 7/27= 0.259
and q2= 0.74
The sample size = n= 27
The population proportion = p1= 0.4
q1= 0.6
We formulate the null and alternate hypotheses that the new program is effective
H0: p2> p1 vs Ha: p2 ≤ p1
The test statistic is
z= p2- p1/√ p1q1/n
z= 0.259-0.4/ √0.4*0.6/27
z= -0.141/0.09428
z= -1.496
The significance level ∝ is 0.05
The critical region for one tailed test is z ≤ ± 1.645
Since the calculated value of z= -1.496 does not fall in the critical region z < -1.645 we conclude that the new program is effective. We fail to reject the null hypothesis .
It would be 1.3 less than the other.
