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max2010maxim [7]
3 years ago
10

A calculus student takes a 20-question, multiple choice test with 5 answer choices for each question. find the mean and standard

deviation of the number of questions that he/she gets correct
Mathematics
1 answer:
mario62 [17]3 years ago
4 0
Suppose the student guesses the answers, we shall consider this a binomial probability problem of success. This implies that getting a question right is p=1/5.
The number of questions is n=20 questions.
The mean of binomial distribution is 
mean=n*p= 20*1/5=4

b] The standard deviation of a binomial distribution is given by:
σ=√(n*p*(1-p))
=√(20*0.2*0.8)
=1.79~1.8

Answer:
μ=4 ; σ=1.8
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Answer:

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Step-by-step explanation:

Geometric series states that a series in which a constant ratio is obtained by multiplying the previous term.

Sum of the geometric series is given by:

S_n = \frac{a(1-r^n)}{1-r}

where a is the first term and n is the number of term.

Given the series: 1+2+4+8+.................+a_{10}

This is a geometric series with common ratio(r) = 2

We have to find the sum of the series for 10th term.

⇒ n = 10 and a = 1

then;

S_n = \frac{1(1-2^{10})}{1-2} =\frac{1-1024}{-1} =\frac{-1023}{-1}=1023

Therefore, the sum of the given series is 1023



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Answer:

t = 4 seconds

Step-by-step explanation:

The height of the projectile after it is launched is given by the function :

h(t)=-16t^2+32t+128

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We need to find after how many seconds will the projectile land back on the ground. When it land, h(t)=0

So,

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The above is a quadratic equation. It can be solved by the formula as follows :

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t=\dfrac{-32\pm \sqrt{(32)^2-4\times (-16)(128)} }{2\times (-16)}\\\\t=\dfrac{-32+ \sqrt{(32)^2-4\times (-16)(128)} }{2\times (-16)}, \dfrac{-32\- \sqrt{(32)^2-4\times (-16)(128)} }{2\times (-16)}\\\\t=-2\ s\ \text{and}\ 4\ s

Neglecting negative value, the projectile will land after 4 seconds.

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3 years ago
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Answer:

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