Answer:
Step-by-step explanation:
Given that the housing market has recovered slowly from the economic crisis of 2008. Recently, in one large community, realtors randomly sampled 38 bids from potential buyers to estimate the average loss in home value.
s = sample std deviation = 3000
Sample mean = 9379
Sample size n = 38
df = 37
Std error of sample mean = 
confidence interval 95% = Mean ± t critical * std error
=Mean ±1.687*486.66 = Mean ±821.003
=(8557.997, 10200.003)
a) If std deviation changes to 9000 instead of 3000, margin of error becomes 3 times
Hence 2463.008
b) The more the std deviation the more the width of confidence interval.
Answer:
Since the calculated value of t =-0.427 does not fall in the critical region so we accept H0 and conclude that there is enough evidence to show that mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
Step-by-step explanation:
The given data is
Difference d= -24 -12 -55 -15 -30 -60 -14 -21 -48 -12 -25 -53 -61 -69 -80
∑ d= -579
∑d²= 29871
1) Let the hypotheses be
H0: ud= 25 against the claim Ha: ud ≠25
H0 : mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
Ha: mean difference in the age of onset of symptoms and age of diagnosis is not 25 months.
2) The degrees of freedom = n-1= 15-1= 14
3) The significance level is 0.05
4) The test statistic is
t= d`/sd/√n
The critical region is ║t║≤ t (0.025,14) = ±2.145
d`= ∑di/n= -579/15= -38.6
Sd= 23.178 (using calculators)
Therefore
t= d`/ sd/√n
t= -38.6/ 23.178√15
t= -1.655/3.872= -0.427
5) Since the calculated value of t =-0.427 does not fall in the critical region so we accept H0 and conclude that there is enough evidence to show that mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
Answer:
Step-by-step explanation:
With what?
Answer:
Step-by-step explanation:
A
According to the exercise we can say that the explanatory variable will be hours / weeks of study.
The response variable is GPA.
B
We definitely found that between the variables there is a weak or fragile relationship, neither negative nor positive nor linear.
C)
1.Observational study, since we observe that the only variables that will influence the results of the study are the observations of the students
2.No. This study is observational and its characteristics are not sufficient to conclude that studying more hours leads to obtaining a higher GPA.
