The amount of time a certain brand of light bulb lasts is normally distribued with a mean of 1800 hours and a standard deviation of 35 hours. Using the empirical rule, what percentage of light bulbs last between 1765 hours and 1835 hours?

68% of light bulbs last between 1765 hours and 1835 hours.

Step-by-step explanation:

The empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below

68% of data falls within the first standard deviation from the mean.

95% fall within two standard deviations.

99.7% fall within three standard deviations.

From the information given, the mean is 1800 hours and the standard deviation is 35 hours.

1 standard deviation = 1 × 35 = 35

1800 - 35 = 1765 hours

1800 + 35 = 1835 hours

Therefore, 68% of light bulbs last between 1765 hours and 1835 hours.

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions

y < -3

step-by-step explanation:

-3y - 2 > 7

-3y -2 + 2 > 7+2

-3y > 9

-3y/-3 < 9/-3   (change the inequality sign when multiplying or dividing by a negative number)

y < -3