Answer:
1. 
2. 
3. 
4. 
Step-by-step explanation:
Answer:
The probability is 0.0775
The expected value is 4.75 clubs
The standard deviation is 1.8875 clubs
Step-by-step explanation:
The variable X follows a binomial distribution, because we have n identical and independent events (19 cards) with a probability p of success and 1-p of fail (there is a probability of 1/4 to be club and 3/4 to be diamond, heart or spade). Then, the probability that x of the n cards are club is:

So, the probability P of drawing at least 8 clubs is:
P = P(8) + P(9) + P(10) + ... + P(18) + P(19)
Replacing, the values of x, from 8 to 19, on the equation above, we get:
P = 0.0775
Additionally, the expected value E(x) and standard deviationS(x) for this distribution is given by:
E(x)=np = 19(0.25) = 4.75

Answer:
b. multiply the bottom equation by 2
Step-by-step explanation:
it would eliminate y
Answer:
y = 2.1x +5, 21 miles
Step-by-step explanation:
We will denote miles as "x"
Since she tipped the driver $5, that is a flat rate and that will be our y-intercept. Since it costs $2.10 per mile, we need to multiply that number by the number of miles
So our equation will be y = 2.1x +5
In order to figure out how many miles Ann lives from the airport, we need to substitute y for her grand total that she was charged
This gives us 49.10 = 2.10x + 5
First we need to subtract 5 from each side to get 44.10 = 2.10x
We then need to divide both sides by 2.10 to get 21 = x
Ann drove 21 miles
11 days, 21 hours, and 52 minutes have elapsed
(this answer is assuming he would have a normal heart rate of 70 bpm)
First, you would divide 1,200,703 by 70:
1,200,703/70=17,152.9
This is the amount of minutes that have elapsed.
Then, you convert the minutes to hours by dividing by 60:
17,152.9/60=285.8816667 (285 hours and 52 minutes)
This gives you how many hours and minutes have elapsed.
Finally, you calculate the number of days that have elapsed by dividing 285 by 24 (there are 24 hours in a day):
285/24=11.875 (11 days and 21 hours).
Put all of the amounts together to get the final answer:
11 days, 21 hours, and 52 minutes have elapsed