Answer:
a and b.
Step-by-step explanation:
I’ll explain by giving an example.
Let’s say that: a=3;b=4;c=5; => they all are consecutive -> their sum is 12.
=> if we use a) n=3 => 3*n+3=3*3+3=12 => correct.
b) n+(n+1)+(n+2)= 3+4+5=12=> correct.
c)n+2n+3n=3+6+9=18=>incorrect.
d)3n=3*3=9=>incorrect.
Using the t-distribution to build the 99% confidence interval, it is found that:
- The margin of error is of 3.64.
- The 99% confidence interval for the population mean is (19.36, 26.64).
<h3>What is a t-distribution confidence interval?</h3>
The confidence interval is:
In which:
- is the sample mean.
- s is the standard deviation for the sample.
The critical value, using a t-distribution calculator, for a two-tailed 95% confidence interval, with 21 - 1 = 20 df, is t = 2.086.
The other parameters are given as follows:
The margin of error is given by:
Hence the bounds of the interval are:
The 99% confidence interval for the population mean is (19.36, 26.64).
More can be learned about the t-distribution at brainly.com/question/16162795
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Answer:
DEF
Step-by-step explanation:
The other triangle is a reflection
Answer:
x=3/22 ; y=-9/44
Step-by-step explanation:
1/2x+1/3=4
=>1/2x=4-1/3
=>1/2x=(12-1)/3
=>1/2x=11/3
=>22x=3
=>x=3/22....(1)
then,
3x+2y
2y=-3 . (3/22)
y=-9/44