(Will mark brainliest Sixty percent of all children in a school do not have cavities. The probability, rounded to four decimal places, that in a random sample of 9 children selected from this school, at least 6 do not have cavities is:

probability[Number of 6 random sample do not have cavities] = 0.8

Step-by-step explanation

Given:

Number of student do not have cavities = 60%

Number of random sample = 9 children

Find:

Probability[Number of 6 random sample do not have cavities]

Computation:

n = 9

p = 60% = 0.6

P(At least 6)  

Probability[Number of 6 random sample do not have cavities] = 1 - P(Less than 6)  

Probability[Number of 6 random sample do not have cavities] = 1 - P(Less than or equal to 6)

Probability[Number of 6 random sample do not have cavities] = 0.8

es una operación aritmética.

step-by-step explanation:

no se que fórmula requiera, pero te puedo decir que es adición. deberías revisar porque tema vas y ver que fórmulas puedes aplicar.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.