Here is a weather thermometer. Three of the numbers have been left off.

A) Write the sequence of natural numbers which are multiplied by 3 ?

Volgvan

Answer:

a) 3, 6, 9, 12, 15,..., $3\cdot n$ , b) 4, 7, 10, 13, 16,..., $3\cdot n +1$ , c) Both sequences are arithmetic.

Step-by-step explanation:

a) The sequence of natural numbers which are multiplied by 3 are represented by the function $f(n) = 3\cdot n$ , $n\in \mathbb{N}$ . Let see the first five elements of the sequence: 3, 6, 9, 12, 15,...

b) The sequence of natural numbers which are multiplied by 3 and added to 1 is represented by the function $f(n) = 3\cdot n + 1$ , $n\in \mathbb{N}$ . Let see the first five elements of the sequence: 4, 7, 10, 13, 16,...

c) Both sequences since differences between consecutive elements is constant. Let prove this statement:

(i) $f(n) = 3\cdot n$

$\Delta f = f(n+1) -f(n)$

$\Delta f = 3\cdot (n+1) -3\cdot n$

$\Delta f = 3$

(ii) $f(n) = 3\cdot n +1$

$\Delta f = f(n+1)-f(n)$

$\Delta f = [3\cdot (n+1)+1]-(3\cdot n+1)$

$\Delta f = 3$

Both sequences are arithmetic.

8 0

3 years ago

A car maintains a speed of 23 mi/h for 5 seconds. It then accelerates to a speed of 46 mi/h in 5 seconds. It maintains that spee

Vika [28.1K]

The answer is a because it starts at 0 then goes up to 23 and then it goes up to 46.

6 0

3 years ago

Read 2 more answers

Julie drew a picture of her rectangular garden,. In her picture,the length of her garden is 7/8 inches and the width is 3/4 inch

stepan [7]

Answer:

21/32 square inches.

Step-by-step explanation:

The area of a rectangle = length x width

The area of her picture = length x widht

= 7/8 x 3/4

= 21/32

The area of her picture is 21/32 square inches.

Yes, I agree the area of the picture is 21/32 square inches.

The area must be in square inches. So she need to specify it.

Thank you.

5 0

3 years ago

A manufacturer of Christmas light bulbs knows that 10% of these bulbs are defective. It is known that light bulbs are defective

Inessa05 [86]

Answer:

(a) P(X $\leq$ 20) = 0.9319

(b) Expected number of defective light bulbs = 15

Step-by-step explanation:

We are given that a manufacturer of Christmas light bulbs knows that 10% of these bulbs are defective. It is known that light bulbs are defective independently. A box of 150 bulbs is selected at random.

Firstly, the above situation can be represented through binomial distribution, i.e.;

$P(X=r) = \binom{n}{r} p^{r} (1-p)^{2} ;x=0,1,2,3,....$

where, n = number of samples taken = 150

r = number of success

p = probability of success which in our question is % of bulbs that

are defective, i.e. 10%

Now, we can't calculate the required probability using binomial distribution because here n is very large(n > 30), so we will convert this distribution into normal distribution using continuity correction.

So, Let X = No. of defective bulbs in a box

Mean of X, $\mu$ = $n \times p$ = $150 \times 0.10$ = 15

Standard deviation of X, $\sigma$ = $\sqrt{np(1-p)}$ = $\sqrt{150 \times 0.10 \times (1-0.10)}$ = 3.7

So, X ~ N( $\mu = 15, \sigma^{2} = 3.7^{2})$

Now, the z score probability distribution is given by;

Z = $\frac{X-\mu}{\sigma}$ ~ N(0,1)

(a) Probability that this box will contain at most 20 defective light bulbs is given by = P(X $\leq$ 20) = P(X < 20.5) ---- using continuity correction

P(X < 20.5) = P( $\frac{X-\mu}{\sigma}$ < $\frac{20.5-15}{3.7}$ ) = P(Z < 1.49) = 0.9319

(b) Expected number of defective light bulbs found in such boxes, on average is given by = E(X) = $n \times p$ = $150 \times 0.10$ = 15.

5 0

3 years ago

If kip spent $21.45 at the fair, how many tickets did he buy?

azamat

Can you add the price of the tickets?

4 0

3 years ago