All categories

3 years ago

The age of some lecturers are 42,54,50,54,50,42,46,46,48 and 48 calculate the mean age and standard deviation

Mathematics

1 answer:

rjkz [21]3 years ago

3 0

Answer:

Mean age: 48

Standard deviation: 4

Step-by-step explanation:

a) Mean

The formula for Mean = Sum of terms/ Number of terms

Number of terms

= 42 + 54 + 50 + 54 + 50 + 42 + 46 + 46 + 48+ 48/ 10

= 480/10

= 48

The mean age is 48

b) Standard deviation

The formula for Standard deviation =

√(x - Mean)²/n

Where n = number of terms

Standard deviation =

√[(42 - 48)² + (54 - 48)² + (50 - 48)² +(54 - 48)² + (50 - 48)² +(42 - 48)² + (46 - 48)² + (46 - 48)² + (48 - 48)² + (48 - 48)² / 10]

= √-6² + 6² + 2² + 6² + 2² + -6² + -2² + -2² + 0² + 0²/10

=√36 + 36 + 4 + 36 + 4 + 36 + 4 + 4 + 0 + 0/ 10

=√160/10

= √16

= 4

The standard deviation of the ages is 4

You might be interested in

Pls need help w this question

zhuklara [117]

Ok here me out.... 25

4 0

2 years ago

A tattoo enthusiast website claims that :

KATRIN_1 [288]

Answer:

The probability that a person is a Millennial given that they have tattoos is 0.5069 (50.69%) or about 0.51 (51%).

Step-by-step explanation:

We have here a case where we need to use Bayes' Theorem and all conditional probabilities related. Roughly speaking, a conditional probability is a kind of probability where an event determines the occurrence of another event. Mathematically:

$\\ P(A|B) = \frac{P(A \cap B)}{P(B)}$

In the case of the Bayes' Theorem, we have also a conditional probability where one event is the sum of different probabilities.

We have a series of different probabilities that we have to distinguish one from the others:

The probability that a person has a tattoo assuming that is a Millennial is:

$\\ P(T|M) = 0.47$

The probability that a person has a tattoo assuming that is of Generation X is:

$\\ P(T|X) = 0.36$

The probability that a person has a tattoo assuming that is of Boomers is:

$\\ P(T|B) = 0.13$

The probability of being of Millennials is:

$\\ P(M) = 0.22$

The probability of being of Generation X is:

$\\ P(X) = 0.20$

The probability of being of Boomers is:

$\\ P(B) = 0.22$

Therefore, the probability of the event of having a tattoo P(T) is:

$\\ P(T) = P(T|M)*P(M) + P(T|X)*P(X) + P(T|B)*P(B)$

$\\ P(T) = 0.47*0.22 + 0.36*0.20 + 0.13*0.22$

$\\ P(T) = 0.204$

For non-independent events that happen at the same time, we can say that the probability of occurring simultaneously is:

$\\ P(M \cap T) = P(M|T)*P(T)$

$\\ P(T \cap M) = P(T|M)*P(M)$

But

$\\ P(M \cap T) = P(T \cap M)$

Then

$\\ P(M|T)*P(T) = P(T|M)*P(M)$

We are asked for the probability that a person is a Millennial given or assuming that they have tattoos or P(M | T). Solving the previous formula for the latter:

$\\ P(M|T)*P(T) = P(T|M)*P(M)$

$\\ P(M|T) = \frac{P(T|M)*P(M)}{P(T)}$

We have already know that

$\\ P(T|M) = 0.47\;P(M) = 0.22\;and\;P(T) = 0.204$ .

Therefore

$\\ P(M|T) = \frac{0.47*0.22}{0.204}$

$\\ P(M|T) = 0.50686 \approx 0.51$

Thus, the probability that a person is a Millennial given that they have tattoos is 0.5069 (50.69%) or about 0.51 (51%).

5 0

3 years ago

Just tell me the answer I have 5 min

skad [1K]

I think the answer is 21. I’m not sure but if I remember it’s 40 + 20 = 60. 180 - 60 = 120 and then it’s a vertical angle which is equal so then it would be 120 + 39 = 159. Then 180 - 159 = 21. Sorry if this is wrong I haven’t done this in a while. Have a good day!

3 0

2 years ago

Solve each inequality below. Represent the solutions on number lines. 7x − 2 < 3 + 2x

LekaFEV [45]

Hi, I would be glad to help you here.

<span>7x − 2 < 3 + 2x

Move terms

7x - 2x - 2 < 3

Collect the like terms

(7x - 2x) = 5x (<3 + 2 stays the same)

Calculate

5x (<3 + 2 = 5)

5x <5

Divide both sides of the inequality by (5) giving you,

x < 1

So, finally in a total the correct answer here is (x < 1)

</span>

6 0

2 years ago

A __ fraction is a fraction whose denominator is 10,100,or some other multiple of 10.

Alexxandr [17]

Answer: A decimal fraction is a fraction whose denominator is 10,100,or some other multiple of 10.

Step-by-step explanation:

8 0

3 years ago