During a two-day golf tournament, Fran scored +3 on the first day and -1

Samantha reports that 60% of the first year students at her university think they should be able to bring a car to campus. She a

Nostrana [21]

Answer:

D) the standard error for her sample is 15

Step-by-step explanation:

Samantha is 95% certain that between 50% and 70% of the first year students agree that they should be able to bring a car to campus.

Here

95% is the confidence level.
The range between 50% and 70% indicates 95% confidence interval.
60% is the average proportion of the first year students at her university think they should be able to bring a car to campus.
10% (0.1) is the margin of error from the mean

Since standard error can be obtained by dividing margin of error by the z-statistic of the confidence level which is 1.96. The standard error for her sample $\frac{0.1}{1.96}$ does not equal to 15.

4 0

3 years ago

Find the sum of the first 20 terms of the arithmetic sequence 4, -4, -12, -20

Vsevolod [243]

Answer:

The sum of the first 20 terms is -1440.

Step-by-step explanation:

We want to find the sum of the first 20 terms of the arithmetic sequence:

4, -4, -12, -20...

The sum of an arithmetic sequence is given by:

$\displaystyle S=\frac{k}{2}(a+x_k)$

Where k is the number of terms, a is the initial term, and x_k is the last term.

Since we want to find the sum of the first 20 terms, k = 20.

Our initial term a is 4.

Our last term is also the 20th term as we want the sum of the first 20 terms.

To find the 20th term, we can write an explicit formula for our sequence. The explicit formula for an arithmetic sequence is given by:

$x_n=a+d(n-1)$

Where a is the initial term, d is the common difference, and n is the nth term.

Our initial term is 4. From the sequence, we can see that our common difference is -8 since each subsequent term is eight less than the previous term. Therefore:

$x_n=4-8(n-1)$

Then the last or 20th term is:

$x_{20}=4-8(20-1)=4-8(19)=-148$

Therefore, the sum of the first 20 terms are:

$\displaystyle\begin{aligned} S_{20}&=\frac{(20)}{2}\left((4)+(-148))\\&=10(-144) \\&= -1440\end{aligned}$

5 0

2 years ago

Read 2 more answers

Among 500 freshmen pursuing a business degree at a university, 315 are enrolled in an economics course, 213 are enrolled in a ma

scoundrel [369]

Answer:

Step-by-step explanation:

Given that among 500 freshmen pursuing a business degree at a university, 315 are enrolled in an economics course, 213 are enrolled in a mathematics course, and 123 are enrolled in both an economics and a mathematics course.

From the above we find that

a) either economics of Math course is

$315+213-123 =405$