Answer:
There is an association because the relative frequencies by row are different.
Step-by-step explanation:
The relative frequencies by row are:
90 perfect t-shirts out of 90+6=96 t-shirts is:
90/96 = 0.9375
6 flawed t-shirts out of 96 t-shirts is:
6/96 = 0.0625
40 perfect sweatshirts out of 40+10=50 sweatshirts is:
40/50 = 0.8
10 flawed sweatshirts out of 50 sweatshirts is:
10/50 = 0.2
The relative frequencies by row are different; this means there is an association.
Answer:
The condition are
The Null hypothesis is 
The Alternative hypothesis is
The check revealed that
There is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is n = 20
The sample mean is 
The standard deviation is 
The Null hypothesis is 
The Alternative hypothesis is
So i will be making use of
level of significance to test this claim
The critical value of
from the normal distribution table is 
Generally the test statistics is mathematically evaluated as

substituting values


Looking at the value of t and
we see that
so we fail to reject the null hypothesis
This implies that there is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons.
Answer:
(B) The correct interpretation of this interval is that 90% of the students in the population should have their scores improve by between 72.3 and 91.4 points.
Step-by-step explanation:
Confidence interval is the range the true values fall in under a given <em>confidence level</em>.
Confidence level states the probability that a random chosen sample performs the surveyed characteristic in the range of confidence interval. Thus,
90% confidence interval means that there is 90% probability that the statistic (in this case SAT score improvement) of a member of the population falls in the confidence interval.