In order to find zeroes of a function, we will probably want to use our quadratic formula.

-b±√b^2-4(a)(c)/2a

If we know our values, we can plug it in.

Our values:

A=1 (Since there is no number in front of x, it is an assumed 1)
B=17
C=72

Now, We can plug it into our formula.

BE SURE TO PUT PARENTHESIS AROUND ALL TERMS!

-(17)±√(17)^2-4(1)(72)/2(1)

Now we can type it into a calculator!

When we plug it into the formula. It gives us two real solutions (or zeroes) which are represented as:

-8 & -9.

4 0

2 years ago

A baseball player has a batting average of 0.25. What is the probability that he has exactly 2 hits in his next 7 at bats

marissa [1.9K]

Answer:

The probability that he has exactly 2 hits in his next 7 at-bats is 0.3115.

Step-by-step explanation:

We are given that a baseball player has a batting average of 0.25 and we have to find the probability that he has exactly 2 hits in his next 7 at-bats.

Let X = Number of hits made by a baseball player

The above situation can be represented through binomial distribution;

$P(X = r) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r}; x = 0,1,2,......$

where, n = number of trials (samples) taken = 7 at-bats

r = number of success = exactly 2 hits

p = probability of success which in our question is batting average

of a baseball player, i.e; p = 0.25

SO, X ~ Binom(n = 7, p = 0.25)

Now, the probability that he has exactly 2 hits in his next 7 at-bats is given by = P(X = 2)

P(X = 2) = $\binom{7}{2}\times 0.25^{2} \times (1-0.25)^{7-2}$

= $21 \times 0.25^{2} \times 0.75^{5}$

= 0.3115

5 0

3 years ago