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andreyandreev [35.5K]
2 years ago
13

An article presents a study of health outcomes in women with symptoms of heart disease. In a sample of 110 women whose test resu

lts suggested the presence of coronary artery disease, the mean peak systolic blood pressure was 169.9 mmHg, with a standard deviation of 24.8 mmHg. In a sample of 225 women whose test results suggested an absence of coronary artery disease, the mean peak systolic blood pressure was 163.3 mmHg, with a standard deviation of 25.8 mmHg. Find a 95% confidence interval for the difference in mean systolic blood pressure between these two groups of women. (Round the final answers to three decimal places.)
Mathematics
1 answer:
REY [17]2 years ago
4 0

Answer:

(0.869, 12.33104)

Step-by-step explanation:

N1 = 110

N2 = 225

S1 = 24.8

S2 = 25.8

Bar x1 = 169.9

Bar x2 = 163.3

Difference in mean = 169.9 - 163.3 = 6.6

We use the z score

Alpha = 0.05

Z critical value at this alpha level = 1.96

We find standard error

√s1²/n1+s2²/n2

= √(24.8²/110 + 25.8²/225)

= 2.9239

Confidence interval

6.6 +-1.96(2.924)

(6.6-5.73104, 6.6+5.73104)

= (0.869, 12.331)

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zhuklara [117]

Step-by-step answer:

Given:

A triangle

Perimeter  = 60 cm

longest side = 4* shortest side (x)

Solution:

longest side = 4x

shortest side = x

third (intermediate side = 60 -x -4x = 60-5x

The triangle inequality specifies that the sum of the two shorter sides must be greater than the longest side to form a triangle.  Hence

x + y > 4x

x + 60-5x > 4x

60 - 4x > 4x

8x < 60

x < 60/8 = 7.5, or

x < 7.5

Therefore to form a triangle, x (shortest side) must be less than 7.5 cm.

Examine the options: both 7 and 5 are both less than 7.5 cm.

40, 30 and 25 all have a problem because the longest side (4 times longer) will exceed the perimeter of 60.

Now also examine cases where 4x is NOT the longest side, in which case we need

4x>=y

or

4x >= 60-5x

9x >=60

x >= 6.67

so x=5 will not qualify, because 4x will no longer be the longest side.

The only valid option is x=7 cm

The side lengths for x=7 and x=5 are, respectively,

(7, 25, 28)

5, 20, 35  (in which case, the longest side is no longer 4x=20, so eliminated)

7 0
3 years ago
James has 858 feet of rope. There are 18 teams of hikers.
soldier1979 [14.2K]

Answer:

48 or 47

Step-by-step explanation:

858/18 = 47.6

6 0
3 years ago
Could someone help me find the domain and range? Thank you
Sonja [21]
(-4,0) (-3,3) (-1,0) (0,-3) (1,-5) (3,0)
So, domain numbers are -4, -3, -1, 0, 1, 3
Range are 0, 3, -3,-5,
Just take the ordered pairs and the Xs is the domain and the Ys are the range
8 0
3 years ago
I really need help with this, I'll give Brainliest to whoever answers correctly!
alexgriva [62]

Answer:

B) 5 5/8in x 9in is your answer

Step-by-step explanation:

First add the bottom numbers together (9+6+9) which gives you 24. Then multiply both sides by 3/8 (15 x 3/8= 5 <u>5/8</u>) and (24 x 3/8= <u>9</u>) making your answer 5 5/8 x 9

5 0
3 years ago
Jack is building a deck that is 8 ft by 27.63 ft. He has the base built; he just needs to cover the surface with wood. When he g
gulaghasi [49]
The area of the deck is :
A ( deck ) = 8 * 27.63 = 221.04 ft²
The area of the sheet of wood:
A ( sheet ) = 4 * 8 = 32 ft²
221.04 : 32 = 6.9 ≈ 7 ( we need a whole number )
Answer: He should buy 7 sheets of wood to cover the surface of the deck.
5 0
3 years ago
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