Answer:
20 people only buy dvds.
Step-by-step explanation:
There are two groups in this problem. One group of people that buys dvds and one that buys blu rays. The total amount of people who buy blu rays is 300, but there's an intersection between the groups and the size of this is 280 people who actually buy both. In order to find out how many people only buy DVDs we first need to figure out how many only buy blu-rays. That is:
people who only buy blu rays = people who buy blu rays - people who buys blu rays and dvds
people who only buy blu rays = 300 - 280 = 20
We can now calculate the amount of people who only buy dvds and that is:
people who only buy dvds =total amount of people - ( people who only buy blu rays + people who buy both)
people who only buy dvds = 320 - (20 + 280) = 320 - 300 = 20 people
Now we will use cross products
6n = 1630 Now we divide both sides by 6
<u>6n</u> = <u>1630
</u>6 6
n= 271.666..... which rounds to
272 as the nearest integer
Answer:
probability of a Type I error=0.002
Step-by-step explanation:
Null hypothesis : The individual is telling the truth.
Alternative hypothesis : The individual is not telling the truth.
a)
P(Type I error) = P( rejecting the null hypothesis when it is true) = 0.002
The answer is D, or 168.
The cheese can be any one out of 3 = 3 choices. For each of those . . .
The first topping can be any one of 8. For each of those . . .
The second topping can be any one of the remaining 7 . For each of those . . .
The third topping can be any one of the remaining 6 .
Total number of ways to assemble a pizza = (3 x 8 x 7 x 6) = 1,008 ways.
<span>BUT . . . </span>
You could choose the SAME 3 toppings in (3 x 2) = 6 different ways, and
nobody could tell the difference once they were selected. All 6 different
ways would result in the same pizza.
So, out of the 1,008 total different ways there are of choosing ingredients,
<span>there are only ( 1,008 / 6 ) = </span>168<span> different and distinct pizzas.</span>