Remove parentheses
2c - 4 + 5c + 11
Combine like terms
Answer: 7c + 7
Answer:
The answer is x = -7.7 ans x = -1.3
Step-by-step explanation:
Here is the work I did. I used the quadratic formula. Sorry about my bad handwriting.
Answer:
The 90% confidence interval for the mean nicotine content of this brand of cigarette is between 20.3 milligrams and 30.3 milligrams.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 9 - 1 = 8
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.8595
The margin of error is:
M = T*s = 1.8595*2.7 = 5
In which s is the standard deviation of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 25.3 - 5 = 20.3 milligrams
The upper end of the interval is the sample mean added to M. So it is 25.3 + 5 = 30.3 milligrams.
The 90% confidence interval for the mean nicotine content of this brand of cigarette is between 20.3 milligrams and 30.3 milligrams.
Answer:
T < - 4°C
Step-by-step explanation:
Given that Mariana wears her coat only when temperature is colder than - 4°C
Recall that lower temperature values indicate higher degree of coldness ;
Hence, Mariana will only wear her coat when temperature values are lesser than - 4°C ; this means that the temperature at that period is colder than - 4°C.
Hence, the inequality expression which is only true for temperatures when Mariana wears her coat can be written as :
Temperature = T
T < - 4°C