Answer: 
Step-by-step explanation:
Given : Sample size : n= 9
Degree of freedom = df =n-1 =8
Sample mean : 
sample standard deviation : 
Significance level ; 
Since population standard deviation is not given , so we use t- test.
Using t-distribution table , we have
Critical value = 
Confidence interval for the population mean :

90% confidence interval for the mean value will be :






Hence, the 90% confidence interval for the mean value= 
Stan's heart rate, in beats per minute, was measured 20 times at random. The results are 82, 84, 98, 112, 97, 93, 91, 87, 112, 8
Licemer1 [7]
Answer:
(80.4942, 94.9052)
Step-by-step explanation:
The sample mean is x = 87.7.
The sample standard deviation is s = 11.26.
At 99% confidence and 19 degrees of freedom, the critical value is t = 2.861.
The confidence interval is:
x ± t (s/√n)
87.7 ± 2.861 (11.26 / √20)
87.7 ± 7.2053
(80.4947, 94.9053)
Answer:
A - the real answer is 7
Step-by-step explanation:
g²=49 (square root 49 to get 7)
B) not sure - possibly wrote the negative sign as a mistake