2d + 7 = 9 please help me!

A random sample of 36 students at a community college showed an average age of 25 years. Assume the ages of all students at the

Pavel [41]

Answer:

98% confidence interval for the average age of all students is [24.302 , 25.698]

Step-by-step explanation:

We are given that a random sample of 36 students at a community college showed an average age of 25 years.

Also, assuming that the ages of all students at the college are normally distributed with a standard deviation of 1.8 years.

So, the pivotal quantity for 98% confidence interval for the average age is given by;

P.Q. = $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample average age = 25 years

$\sigma$ = population standard deviation = 1.8 years

n = sample of students = 36

$\mu$ = population average age

So, 98% confidence interval for the average age, $\mu$ is ;

P(-2.3263 < N(0,1) < 2.3263) = 0.98

P(-2.3263 < $\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.3263) = 0.98

P( $-2.3263 \times {\frac{\sigma}{\sqrt{n} }$ < ${\bar X - \mu}$ < $2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ) = 0.98

P( $\bar X - 2.3263 \times {\frac{\sigma}{\sqrt{n} }$ < $\mu$ < $\bar X +2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ) = 0.98

98% confidence interval for $\mu$ = [ $\bar X - 2.3263 \times {\frac{\sigma}{\sqrt{n} }$ , $\bar X +2.3263 \times {\frac{\sigma}{\sqrt{n} }$ ]

= [ $25 - 2.3263 \times {\frac{1.8}{\sqrt{36} }$ , $25 + 2.3263 \times {\frac{1.8}{\sqrt{36} }$ ]

= [24.302 , 25.698]

Therefore, 98% confidence interval for the average age of all students at this college is [24.302 , 25.698].

8 0

3 years ago

-2 3/4 ÷ -1/7= help

Hitman42 [59]

The answer is 19 $\frac{1}{4}$

First you must set up the equation

$-2\frac{3}{4}$ ÷ $-\frac{1}{7}$

First, you must make the mixed number a improper fraction

$-\frac{11}{4}$ ÷ $-\frac{1}{7}$

Then you must divide

$\frac{77}{4}$

Finally, simplify

19 $\frac{1}{4}$

3 0

3 years ago

Explain how probability can be used to help a sales person forecast future sales.

Naily [24]

Answer with explanation:

A salesperson can use probability to get an idea of his business as using probability he can estimate his sale of the next month as well, based on the present and previous months sales.

It can help him sort issues or errors he is facing in his business as he will get a complete idea of his business using probability.

Moreover, he can forecast future sales by using a technique which involves assigning percentages or weighting benchmarks in sales cycle, so that he can estimate the expected revenue generated.

For example:

A supermarket sales person can assign probabilities to benchmarks in sale cycle as providing needs analysis (25 % probability), adding new product (50%Probability) , Remove a product ( 75 % probability), closing sale (100% Probability) . If these probabilities are large, then forecast model can be objective.

_____________________________________________________

So just like that by assigning probabilities to benchmarks, a sales person can forecast future sales

6 0

3 years ago

Read 2 more answers

(13÷6)×8+6. question 2. 10×3+(7+8) please show steps Thank you

AysviL [449]

That is how u would do it