Given, the function that shows the proportion of students in a psychology experiment who could remember an eight-digit number correctly for t minutes,

$f(t) = 0.9 - 0.4\ln(t)$

If t = 7 minutes,

$f(7) = 0.9 - 0.4\ln(7)=0.9 - 0.77836=0.12164\approx 0.1$

Hence, the proportion that remembered the number for 7 minutes is 0.1 ( approx )

8 0

2 years ago

A pharmacist needs 500 milliliters of a 20% phenobarbital solution but has only 5% and 25% phenobarbital solutions available. Fi

sladkih [1.3K]

Let x be ml of 5% soln.

let 500-x be ml of 25% soln.

x*.05=.05x

(500-x)*.25=125-.25x

500*.20=100

.05x+125-.25x=100

-.2x=-25

x=-25/-.2

x=125 ml of 5% soln.

500-x=375 ml of 25% soln.

Check:

125*.05= 6.25

375*.25=93.75

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========100

7 0

2 years ago

PLEASE ANSWER QUICKLY

Travka [436]

Answer:

63 :)

Step-by-step explanation:

3 0

2 years ago

What is 100 digits of pi

ra1l [238]

Answer:

the first 100 digits of pi are 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679

8 0

2 years ago

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