Which equation represents the line shown on the coordinate grid below

on the last 5 quizzes, marco has earned a total of 21 out of 25 possible points. if he has a perfect score on the next several q

nevsk [136]

Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.

The mean of a data-set is the sum of all observations divided by the number of observations.

In this problem:

In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is $\frac{21}{25} = 0.84$ .
In the next n observations, mean of 1.

Hence, the mean is:

$M = \frac{0.84(5) + n}{5 + n} = \frac{4.2 + n}{5 + n}$

We want the mean to be of 0.9, thus:

$M = 0.9$

$\frac{4.2 + n}{5 + n} = 0.9$

$4.2 + n = 0.9n + 4.5$

$0.1n = 0.3$

$n = \frac{0.3}{0.1}$

$n = 3$

3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.

A similar problem is given at brainly.com/question/25323941

6 0

3 years ago

Suppose that you earned a bachelor's degree and now you're teaching high school. The school district offers teachers the oppor

stepan [7]

Answer:

Step-by-step explanation:

Answer:

a. The amount that is saved at the expiration of the 5 year period is $22,769.20¢

b. The amount of interest is $2,769.20¢

Step-by-step explanation:

Since the amount that is deposited every year for a period of five years is $4,000 and the rate of the interest is 6.5%. We can always calculate the amount that is saved at the expiration of the five years.

We will first state the formula for calculating the future value of annuity:-

Future value of annuity =

$P[\frac{(1 + r)^{t}-1 }{r}]$

Where P is the amount deposited per year.

r is the rate of interest

t is the time or period

and in this case, the actual value of P = $4,000

rate of interest, r is 6.5% = 0.065

time, t is 5 years.

Substituting e, we have:

Fv of annuity =

$4,000[\frac{(1 + 0.065)^{5}-1 }{0.065 }]$

= 4,000 × [((1.065)^5)- 1/0.065]

= 4,000 × [(1.37 - 1)/0.065]

= 4,000 × (0.37/0.065)

= 4,000 × 5.6923

= $22,769.20¢

a. Therefore the amount that is saved at the end of the five (5) years is $22,769.20¢

b. To find the interest, we will calculate the amount of deposit made during the period of five years and subtract the sum from the current amount that is saved ($22,769.29¢).

Since I deposited 4,000 every year for five years, the total amount of deposit I made at the period =

4,000 × 5 = $20,000

The amount of interest is then = $22,769.20¢ - $20,000 = $2,769.20¢

3 0

3 years ago

Solve for x. x + 7 -3 = 1 i need help

MA_775_DIABLO [31]

X+7-3=1 X+4=1 -4 -4 X=-3 Copy exactly how you see it

8 0

3 years ago

Halp me please i don't wanna fail...I wanna pass this test ;--; (MUST BE A EXPRESSION)

vaieri [72.5K]

Answer:

155+27n

Step-by-step explanation:

hope this helps

6 0

3 years ago

Read 2 more answers

An article in Knee Surgery, Sports Traumatology, Arthroscopy, "Arthroscopic meniscal repair with an absorbable screw: results an

igomit [66]

Answer:

Mean = 1.57

Variance=0.31

Step-by-step explanation:

To calculate the mean and the variance of the number of successful surgeries (X), we first have to enumerate the possible outcomes:

1) Both surgeries are successful (X=2).

$P(e_1)=0.90*0.67=0.603$

2) Left knee unsuccessful and right knee successful (X=1).

$P(e_2)=(1-0.9)*0.67=0.1*0.67=0.067$

3) Right knee unsuccessful and left knee successful (X=1).

$P(e_3)=0.90*(1-0.67)=0.9*0.33=0.297$

4) Both surgeries are unsuccessful (X=0).

$P(e_4)=(1-0.90)*(1-0.67)=0.1*0.33=0.033$

Then, the mean can be calculated as the expected value:

$M=\sum p_iX_i=0.603*2+0.067*1+0.297*1+0.033*0\\\\M=1.206+0.067+0.297+0\\\\M=1.57$

The variance can be calculated as:

$V=\sum p_i(X_i-\bar{X})^2\\\\V=0.603(2-1.57)^2+(0.067+0.297)*(1-1.57)^2+0.033*(0-1.57)^2\\\\V=0.603*0.1849+0.364*0.3249+0.033*2.4649\\\\V=0.1115+0.1183+0.0813\\\\V=0.3111$

3 0

3 years ago