A teacher designs a test so a student who studies will pass 90% of the time, but a student who does not study will pass 11% of the time. A certain student studies for 85% of the tests taken. On a given test, what is the probability that student passes?

Using the percentages given, it is found that there is a 0.7815 = 78.15% probability that student passes.

The percentages associated with passing the test are given by:

Hence, adding these percentages:

0.7815 x 100% = 78.15%

There is a 0.7815 = 78.15% probability that student passes.

A similar problem, also involving the use of percentages, is given at link

probability that student passes = 0.7815

Step-by-step explanation:

Given:

Student studies = 85% = 0.85

Student not study = 11% = 0.11

Student who pass = 90% = 0.90

Computation:

P(student not pass) = 1 - 0.85

P(student not pass) = 0.15

probability that student passes = P(Student studies)(Student who pass) + P(Student not study)(student not pass)

probability that student passes = (0.85)(0.90) + (0.15)(0.11)

probability that student passes = 0.765 + 0.0165

probability that student passes = 0.7815

the final amount you will pay is $68.04.

the tip is determined by the pre-tax amount, so we calculate the tip based on the original bill, not after we've added sales tax.

to find the tip:

we can divide 54.00 by 100 to get 1% of 54. then we multiply that by 18.

54 / 100 = .54

.54 x 18 = 9.72

tip = 9.72$

to find the tax:

we can divide 54.00 by 100 to get 1% of 54. then we can multiply that by 8 to get 8%.

54 / 100 = .54

.54 x 8 = 4.32

tax= 4.32

now we can add the tip and tax to the bill to get our total.

54 + 9.72 + 4.32 = 68.04

total: $68.04

step-by-step explanation:

a)(x-2)^2+(y-1)^2=9

step-by-step explanation:

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