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2 years ago

marla has 4.55 in dimes and quarters. if she ha s7 more quarters than dimes, how many quarters doe she have?

Mathematics

1 answer:

Jlenok [28]2 years ago

8 0

Answer:

number of dimes is 8

number of quarters is 15

Step-by-step explanation:

let 'd' = number of dimes

let 'd+7' = number of quarters

.10d + .25(d + 7) = 4.55

.10d + .25d + 1.75 = 4.55

.35d = 2.80

d = 8

q = 7 + 8

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The proportion of students who own a cell phone on college campuses across the country has increased tremendously over the past

galina1969 [7]

Complete Question

The complete question is shown on the uploaded image

Answer:

1 ) The correct option B

2) The correct option is C

3) The correct option is C

4) The correct option is C

Step-by-step explanation:

From the question we are told that

The proportion that own a cell phone is $p = 0.90$

The sample size is n = 15

Generally the appropriate distribution for X is mathematically represented as

$X \ is \ B( n , p )$

$X \ is \ B( 15 , 0.90 )$

Generally the number students that own a cell phone in a simple random sample of 15 students is mathematically represented as

$\mu = n * p$

$\mu = 15 * 0.90$

$\mu = 13.5$

Generally the standard deviation of the number of students who own a cell phone in a simple random sample of 15 students is mathematically represented as

$\sigma = \sqrt{ n * p * q }$

Where q is mathematically evaluated as

$q = 1- p$

$q = 1- 0.90$

$q = 0.10$

$\sigma = \sqrt{ 15 * 0.90 * 0.10 }$

$\sigma = 1.16$

Generally the probability that all students in a simple random sample of 15 students own a cell phone is mathematically represented as

$P(X = 15) = \left 15} \atop {}} \right.C_{15} * p^{15} * q^{15 - 15}$

$P(X = 15) = \left 15} \atop {}} \right.C_{15} * (0.90)^{15} * (0.10 )^{15 - 15}$

From the combination calculator is $\left 15} \atop {}} \right.C_{15} = 1$

$P(X = 15) = 1 * 0.205891 * 1$

$P(X = 15) = 0.206$

7 0

3 years ago

ASAP PLZZZ The axis of symmetry for the graph of the function f start bracket x end bracket equals one-quarter x square plus b x

Lilit [14]

Answer:

$b=-3$

Step-by-step explanation:

The given function is $f(x)=\frac{1}{4}x^2+bx+10$ .

When we compare to $ax^2+bx+=0$ , we have

$a=\frac{1}{4}$ and c=10

The equation of the axis of symmetry of a vertical parabola is:

$x=-\frac{b}{2a}$

Also from the question the axis of symmetry is x=6

We substitute the values to get:

$6=-\frac{b}{2*\frac{1}{4}}$

$6=-\frac{b}{\frac{1}{2}}$

$b=-\frac{1}{2}*6$

$b=-3$

7 0

3 years ago

Read 2 more answers

Help please, I need to figure this problem out

yarga [219]

Answer:

AB is parallel to BE because it is an equilateral triangle.

BE is parallel to EC because it has 2 of the same angles to the same sides are equal.

Hope that helps, it's a tad hard to explain

7 0

3 years ago

today you are going to Ms. Debbie's house who lives 45 minutes from your house. What time should you leave to get there at 5:00?

Whitepunk [10]

60 minutes in an hour. 60-45=15

4:15

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hope it helps

(sorry I didn't know how to explain it)

6 0

2 years ago

Read 2 more answers

4 times the sum of a number and 15 is at least 120.let x represent the number. find the possible values for x

Serga [27]

Answer:

Step-by-step explanation:

4(x+15)>_120

4x+60>_120

-60. -60

4x>_60

— —

4 4

X>_12

3 0

3 years ago