Given : A driving exam consists of 29 multiple-choice questions. Each of the 29 answers is either right or wrong. Suppose the probability that a student makes fewer than 6 mistakes on the exam is 0.26 and that the probability that a student makes from 6 to 20 (inclusive) mistakes is 0.53.

Let X be the number of mistake

$P(X$

$P(6\leq X\leq 20)=0.53$

To find : The probability of each of the following outcomes.

a) A student makes more than 20 mistakes

i.e. $P(X>20)$

$P(X>20)=1-P(X\leq 20)$

$P(X>20)=1-(P(X\leq 5)+P(6\leq X\leq 20))$

$P(X>20)=1-(0.26+0.53)$

$P(X>20)=1-(0.79)$

$P(X>20)=0.21$

b. A student makes 6 or more mistakes

i.e. $P(X\geq 6)=1-P(X$

$P(X\geq 6)=1-0.26$

$P(X\geq 6)=0.74$

c. A student makes at most 20 mistakes

i.e. $P(X\leq 20)=1-P(X>20)$

Using 'a' part $P(X>20)=0.21$

$P(X\leq 20)=1-0.21$

$P(X\leq 20)=0.79$

d. Which two of these three events are complementary?

The complement of an event happening is the exact opposite: the probability of it not happening.

According to definition,

Option a and c are complementary events.

6 0

2 years ago

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A vendor is thinking about changing the number of sweatshirts he brings to

lora16 [44]

Answer:

Medium

Step-by-step explanation:

If a person that would need a little bit of a bigger size they would fit in medium and a small wouldnt fit them. Also a person that wears a small would also benefit because it would be a little bigger so if they grew more it would still fit.

3 0

3 years ago