How is confidence levels determined?

A vaccine, which is currently in use, is known to be 80% effective. A pharmaceutical company has developed a newvaccine and the

storchak [24]

Answer:

The correct answer is B) 18%

Step-by-step explanation:

Note that the vaccine is already and is 80% effective. This means that if the entire population was administered with the vaccine, only 8/10 would gain immunity leaving 2/10 or 0.2 exposed.

If the new vaccine, therefore, is supposed to be 90% effective, it is only pragmatic to administer it against those who do not have immunity which is 0.2 of the existing population.

So to get the percentage that will develop immunity, we have:

0.2 x 0.9 = 0.18 or 18%

Cheers!

4 0

3 years ago

Q 1.) Expand using identities: i. (a+2b)² ii. (5x-3y)² iii. (3a+4)(3a-4)(9a²+16)

Ganezh [65]

Step-by-step explanation:

#1.

(a + 2b)²

Using identity (x + y)² = x² + 2xy + y², we get:

= (a)² + (2b)² + 2 × (a) × (2b)

= a² + 4b² + 4ab

= a² + 4ab + 4b² Ans.

#2.

(5x - 3y)²

Using identity (a - b)² = a² - 2ab + b², we get:

= (5x)² + (3y)² - 2 × (5x) × (3y)

= 25x² + 9y² - 30xy

= 25x² - 30xy + 9y² Ans.

#3.

(3a + 4)(3a - 4)(9a² + 16)

Using identity (x + y)(x - y) = x² - y², we get:

= [(3a)² - (4)²][9a² + 16]

= (9a² - 16)(9a² + 16)

= (9a²)² - (16)²

= 81a⁴ - 256 Ans.

4 0

2 years ago

PLZ HELP! ASAP!!! I WILL GIVE BRAINLIEST

Ira Lisetskai [31]

Answer:

see explanation

Step-by-step explanation:

Using cross- products, that is

$\frac{a}{b}$ = $\frac{c}{d}$ then ad = bc

Given the ratios

$\frac{4}{14}$ and $\frac{6}{21}$

Then equating and using cross- products

If both sides equate then the ratios are equivalent

$\frac{4}{14}$ = $\frac{6}{21}$ , then

4 × 21 = 6 × 14 ⇒ 84 = 84

Both sides are equal thus the ratios are equivalent

8 0

3 years ago

A camping leader bought the items listed in the table for his team. What is the average cost of an item in his purchase?

Rudik [331]

The right answer is Option D: $5.44

Step-by-step explanation:

Given,

Cost of one sun visor = $6.25

Cost of 11 sun visors = 6.25*11 = $68.75

Cost of one sunglasses = $8.90

Cost of 4 sunglasses = 8.90*4 = $35.60

Cost of one water bottle = $9.50

Cost of 8 water bottles = 9.50*8 = $76

Cost of one whistle = $1.75

Cost of 15 whistles = 1.75*15 = $26.25

Total number of items = 11+4+8+15 = 38

Total cost of items = 68.75+35.60+76+26.25 = $206.60

Average = $\frac{Sum\ of\ prices}{No.\ of\ items}$

$Average=\frac{206.60}{38}\\Average=\$5.436$

Rounding off to nearest hundredth

Average = $5.44

The average price of an item is $5.44

The right answer is Option D: $5.44

Keywords: average, sum

Learn more about averages at:

#LearnwithBrainly

7 0

3 years ago

A pair of dice are rolled. What is the probability of rolling 4 or greater?

skelet666 [1.2K]

Answer: option D: 11/12

Explanation:

1) The sample space is formed by 36 pairs: 6×6 = 36.

2) Roolling 4 or more is the same that not rolling 3 or less

3) Rolling 3 or less are (1,1), (1,2), and (2,1). Those are 3 outcomes out of 36.

4) Therefore, not rolling 3 or less (the same that rolling 4 or more) has 36 - 3 = 33 outcomes out of 36.

5) The probability of 33 out of 36 is 33/36

6) Simplify the fraction 33/36 = 11/12

And that is the answer.

6 0

3 years ago