Answer:
The correct option is (c).
Step-by-step explanation:
The assumptions of a two-sample <em>t</em>-test are:
- Independent samples
- Normality
- Equal variances
It is provided that the sample of selected for American adults under the age of 40 is of size, <em>n</em>₁ = 488 and the sample of selected for American adults aged 40 or over is of size, <em>n</em>₂ = 421.
As the sample size is quite large the according to the Central limit theorem the sampling distribution of the sample mean would follow a Normal distribution.
And even if the sample was selected by dialing of various telephone numbers, the sample is not biased since the size of the sample is too large.
So, the sample can be considered as a simple random sample.
Thus, the conditions for two-sample t inference are satisfied.
The correct option is (c).
The answer is : b .... because it makes sense
Answer:
7y-15+2y= 9y-15
9y-15
.....
Step-by-step explanation:
3/5 of 9 miles is 5.4 miles
