The data below represents the number of hours a group of students volunteered at a local soup kitchen.

Bad White [126]

Answer a = 5 and b = 2.

Procedure

Initially means x = 0, then

5 = a*b^0 = a*1 = a, then a = 5

When x = 1, the height is the double of 5, i.e 10 and

10 = a.b^1 = a.b ⇒ b = 10/a = 10/5 = 2

The a = 5 and b = 2, so the equation is y =5(2)^x

7 0

2 years ago

The "cold start ignition time" of an automobile engine is being investigated by a gasoline manufacturer. The following times, in

Nezavi [6.7K]

Answer:

1. Sample Mean = 2.50

2. Sample Variance = 1.35

3. Standard Deviation = 1.16

Step-by-step explanation:

Note: As this question is not complete, similar can be found on internet where following are asked to calculate and here I will calculate these as well.

1. Sample Mean.

2. Sample Variance.

3. Sample Standard Deviation.

So, for sample mean to calculate from the given data points. We need to apply to following formula to calculate sample mean.

Sample Mean = (X1 + X2 + .... + XN) divided by Total number of data points.

Sample Mean = (0.17 + 1.94 + 2.62 + 2.35 + 3.05 + 3.15 + 2.53 + 4.81 + 1.92) divided by (9).

Sample Mean = 2.50

Likewise, from the answer of sample mean we can calculate sample variance by following steps.

Solution:

1. Subtract the obtained mean from each of the data point given.

(0.17 - 2.50) = -2.33

(1.94 - 2.50) = -0.56

(2.62 - 2.50) = 0.12

(2.35 - 2.50) = -0.15

(3.05 - 2.50) = 0.55

(3.15 - 2.50) = 0.65

(2.53 - 2.50) = 0.03

(4.81 - 2.50) = 2.31

(1.92 - 2.50) = -0.58

2. Square each of the differences obtained in step 1.

$-2.33^{2}$ = 5.43

$-0.56^{2}$ = 0.31

$0.12^{2}$ = 0.01

$-0.15^{2}$ = 0.02

$0.55^{2}$ = 0.30

$0.65^{2}$ = 0.42

$0.03^{2}$ = 0.01

$2.31^{2}$ = 5.34

$-0.58^{2}$ = 0.34

3. Sum all of these squares.

(5.43 + 0.31 + 0.01 + 0.02 + 0.30 + 0.42 + 0.01 + 5.34 + 0.34) = 12.18

4. Divide 12.18 by (n-1), where n = 9.

Sample Variance = 12.18/9 = 1.35

Now, by using sample variance, we can calculate standard deviation with easy simple steps.

So, in order to find standard deviation, we just need to take the square root of sample variance that we have already calculated above.

Standard Deviation =  $\sqrt{1.35}$  = 1.16 

Good Luck!

6 0

3 years ago

Louise rewrites the equation to solve for the final cost of the item: c=p(1+r). What is the final cost of a $40 item after an 8%

Mazyrski [523]

$36.8 because if you do 40 times .08 you get 3.2, after that you do 40-3.2 and you get 3.8. Hope this helps.

3 0

3 years ago

Alexandria has been playing at the beach with 329 shells. She is putting shells into rows of 6. How many rows will she need if s

Hitman42 [59]

Answer:

Alexandria requires 55 rows to use all the shells.

Step-by-step explanation:

Given:

Number of Shells = 329

Number of shells in each row = 6

We need to find the number of rows she need if she wants to use all the shells.

Solution:

Now we know that;

number of rows she needs can be calculated by Dividing Number of Shells with Number of shells in each row.

framing in equation form we get;

number of rows = $\frac{329}{6} = 54.83 \approx 55$

Hence Alexandria requires 55 rows to use all the shells.

5 0

3 years ago

Factorise 3(x+y)^2 -5(x+y) + 2

sammy [17]

Answer:

$3x^2+3y^2+6xy-5x-5y+2$

Step-by-step explanation:

$3(x+y)^2 -5(x+y) + 2$

$\mathrm{Expand}\:-5\left(x+y\right)+2$

$-5x-5y+2$

$\mathrm{Simplify}\:3\left(x+y\right)^2$

$3\left(x^2+2xy+y^2\right)$

$3x^2+3\times \:2xy+3y^2$

$3x^2+6xy+3y^2$

$=3x^2+3y^2+6xy-5x-5y+2$

6 0

3 years ago

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