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3 years ago

Four students get 90s on a test, three get 70s, 2 get 60s and one gets an 80. what is the mean test score in this group?

1 answer:

8 0

The mean score will be given by:
mean=
mean=[90*4+70*3+2*60+80]/10
=[360+210+120+80]/10
=770/10
=77
the mean score is 77

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A bank features a savings account that has an annual percentage rate of r=5.2% with interest compounded quarterly. Marcus deposi

Alexxx [7]

Answer:

(A) P = 8,500 , r = 0.052 , n = 4

(B) $12203.47

Step-by-step explanation:

* Lets explain how to solve the problem

- The annual percentage rate is R = 5.2%

- The interest is compounded quarterly

- Marcus deposits $8,500

- The account balance can be modeled by the exponential formula

S(t) = P(1 + r/n)^nt, where

# S is the future value

# P is the present value

# r is the annual percentage rate written as a decimal

# n is the number of times each year that the interest is compounded

# t is the time in years

* Lets solve the problem

∵ P is the present value

∵ Marcus deposits $8,500

∴ The present value is 8,500

∵ r is the annual percentage rate written as a decimal

∵ The annual percentage rate is 5.2%

∴ r = 5.2/100 = 0.052

∵ n is the number of times each year that the interest is compounded

∵ The interest is compounded quarterly

∴ n = 4

# (A)

* P = 8,500 , r = 0.052 , n = 4

# (B)

∵ S(t) = P(1 + r/n)^nt

∵ t is the time in years

∵ Marcus invests the money for 7 years

∴ t = 7

∴ S = 8500(1 + 0.052/4)^(4 × 7)

∴ S = 8500(1.013)^28 = 12203.47

* Marcus will have $12203.47 in 7 years

4 0

3 years ago

3. Using a simulator at space camp, you practice landing your individual spaceship on landing platforms that have different shap

Natalka [10]

Answer:

Area = 66 m^2

Step-by-step explanation:

Area = b h B = 11 H = 6

Area = 11 * 6 = 66 m^2

3 0

2 years ago

How do I solve quadratic equations for example,h(t) = – 0.07t2 + 0.007t + 5

g100num [7]

Answer:

x ≈ -8.402, 8.502

Step-by-step explanation:

The usual methods of solving quadratic equations apply to this one. Any of them can be used: graphing, factoring, completing the square, quadratic formula.

<h3>Solution</h3>

Often, when the coefficients are non-integers and have no obvious relationship to each other, the most convenient method of solution is the quadratic formula. It tells you the solution to ax²+bx+c=0 is ...

$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$

Your equation has the coefficients, a = -0.07, b = 0.007, c = 5, so the solutions are ...

$x=\dfrac{-0.007\pm\sqrt{0.007^2-4(-0.07)(5)}}{2(-0.07)}=\dfrac{-0.007\pm\sqrt{1.400049}}{-0.14}\\\\x=0.05\pm\sqrt{\dfrac{200007}{2800}}=0.05\pm\sqrt{71.4310\overline{714285}}\\\\\boxed{x\approx\{-8.40169,\,8.50169\}}$