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2 years ago

Evaluate the expression when a=

Mathematics

1 answer:

Olin [163]2 years ago

3 0

Answer:

$\frac{2}{15}$

Step-by-step explanation:

Substitute the values for a and c into the expression

- 2c + a

= - 2× $\frac{3}{10}$ + $\frac{11}{15}$

= - $\frac{3}{5}$ + $\frac{11}{15}$

= - $\frac{3(3)}{5(3)}$ + $\frac{11}{15}$

= - $\frac{9}{15}$ + $\frac{11}{15}$

= $\frac{2}{15}$

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An article presents a study of health outcomes in women with symptoms of heart disease. In a sample of 115 women whose test resu

My name is Ann [436]

Answer:

z(s) is in the rejection region we reject H₀ μ₁ = μ₂ and support the claim that at CI 95 % the means of the two groups differs

Step-by-step explanation:

Sample 1:

Sise sample n₁ = 115

μ₁ = 169,9 mmHg

σ₁ = 24,8 mmHg

Sample 2:

Sise sample n₂ = 235

μ₂ = 163,3 mmHg

σ₂ = 25,8 mmHg

We can develop a test hypothesis for differences in means to investigate if the mean peak systolic blood pressure differs between these two groups

We will choose CI = 95 % then significance level α = 5 %

α = 0,05 α/2 = 0,025

z(c) for 0,025 is from z-table z(c) = 1,96

Test Hypothesis:

Null Hypothesis H₀ μ₁ = μ₂

Alternative Hypothesis Hₐ μ₁ ≠ μ₂

The alternative hypothesis tells us that the test is a two-tail test.

z(s) = ( μ₁ - μ₂ ) / √ σ₁²/n₁ + σ₂²/n₂

z(s) = ( 169,9 -163,3 ) / √ (24,8)² /115 + ( 25,8)²/235

z(s) = 6,6 / √5,35 + 2,83

z(s) = 6,6 / 2,86

z(s) = 2,30

Comparing |z(c)| and |z(s)|

z(s) > z(c)

z(s) is in the rejection region we reject H₀ μ₁ = μ₂ and support the claim that at CI 95 % the means of the two groups differs

6 0

2 years ago

Assume that the sales of a certain appliance dealer can be approximaed y sraig were $6000 in 1982 and $ 64,000 in 1987. Let x -

viktelen [127]

Answer:

$y=11,600x+6,000$

Yearly sales in 1990: $98,800.

Step-by-step explanation:

We have been given that the sales of a certain appliance dealer can be approximated by a straight line. Sales were $6000 in 1982 and $ 64,000 in 1987.

If at 1982, $x=0$ then at 1987 x will be 5.

Now, we have two points (0,6000) and (5,64000).

$\text{Slope}=\frac{64,000-6,000}{5-0}$

$\text{Slope}=\frac{58,000}{5}$

$\text{Slope}=11,600$

Now, we will represent this information in slope-intercept form of equation.

$y=mx+b$ , where,

m = Slope,

b = Initial value or y-intercept.

We have been given that at $x=0$ , the value of y is 6,000, so it will be y-intercept.

Substitute values:

$y=11,600x+6,000$

Therefore, the equation $S=11,600x+6,000$ represents yearly sales.

Now, we will find difference between 1990 and 1982.

$1990-1982=8$

To find yearly sales in 1990, we will substitute $x=8$ in the equation.

$S=11,600(8)+6,000$

$S=92,800+6,000$

$S=98,800$

Therefore, the yearly sales in 1990 would be $98,800.

6 0

2 years ago

A necklace has and matching bracelet have two types of beads. The necklace has 12 large beads and 8 small beads and weighs 88 gr

miv72 [106K]

Weight of one large bead is 1.5 grams and weight of one small bead is 8.75 grams.

Step-by-step explanation:

Let,

Weight of one large bead = x

Weight of one small bead = y

According to given statement;

12x+8y=88 Eqn 1

5x+2y=25 Eqn 2

Multiplying Eqn 2 by 4

$4(5x+2y=25)\\20x+8y=100\ \ \ Eqn\ 3\\$

Subtracting Eqn 1 from Eqn 3

$(20x+8y)-(12x+8y)=100-88\\20x+8y-12x-8y=12\\8x=12$

Dividing both sides by 8

$\frac{8x}{8}=\frac{12}{8}\\x=1.5$

Putting x=1.5 in Eqn 1

$12(1.5)+8y=88\\18+8y=88\\8y=88-18\\8y=70$

Dividing both sides by 8

$\frac{8y}{8}=\frac{70}{8}\\y=8.75$

Weight of one large bead is 1.5 grams and weight of one small bead is 8.75 grams.

Keywords: linear equation, elimination method

Learn more about elimination method at:

#LearnwithBrainly

5 0

2 years ago

How do you solve this step by step?

mestny [16]

Answer:

$x = 9$

Step-by-step explanation:

$3x - 5x + 8x = 4x + 18$

$- 2x + 8x = 4x + 18$

$6x = 4x + 18$

$2x = 18$

$x = 9$

8 0

2 years ago

If u= <4,5> and v= <0,-1>, find 2v+5u

GaryK [48]

Answer:

<20,23>

Step-by-step explanation:

u= <4,5> and v= <0,-1>

2v = 2*<0,-1> = <0,-2>

5u = 5* <4,5> = <20,25>

2v+5u = <0,-2> + <20,25>

= <20,23>

4 0

2 years ago

Read 2 more answers