Which of these is a unit rate?

An accelerated life test on a large number of type-D alkaline batteries revealed that the mean life for a particular use before

zheka24 [161]

Answer:

68.2% of the batteries failed between 17.8 and 20.2 hours.

95.44% of the batteries failed between 16.6 and 21.4 hours.

99.97% of the batteries failed between 15.4 and 22.6 hours.

Step-by-step explanation:

The 68-95-99.7 states that, for a normally distributed sample:

68.26% of the measures are within 1 standard deviation of the sample.

95.44% of the measures are within 2 standard deviations of the sample.

99.97% of the measures are within 3 standard deviations of the sample.

In this problem, we have that:

Mean of 19 hours, standard deviation of 1.2 hours.

About 68.26% of the batteries failed between what two values?

This is within 1 standard deviation of the mean. So 68.2% of the batteries failed between 17.8 and 20.2 hours.

About 95.44% of the batteries failed between what two values?

This is within 2 standard deviations of the mean. So 95.44% of the batteries failed between 16.6 and 21.4 hours.

About 99.97% of the batteries failed between what two values?

This is within 3 standard deviations of the mean. So 99.97% of the batteries failed between 15.4 and 22.6 hours.

5 0

2 years ago

Read 2 more answers

DG¯¯¯¯¯¯ , EG¯¯¯¯¯ , and FG¯¯¯¯¯ are perpendicular bisectors of the sides of △ABC . DG=5 cm and BD=12 cm.

jonny [76]

Given that DG, EG, and FG are perpendicular bisectors of the sides of △ABC, this means that the point of intersection, G, is the circumcenter of the triangle and hence AG, BG, and CG are equal.

Given that DG = 5 cm and BD = 12 cm, then

$BG= \sqrt{DG^2+BD^2} \\ \\ = \sqrt{5^2+12^2} = \sqrt{25+144} \\ \\ = \sqrt{169} =13$

Since AG = BG = CG, therefore, CG = 13 cm.

3 0

2 years ago

What is the value of x? 3x−8=(8x+4 ----- 2

stepladder [879]

3x-8 = 8x+4

subtract 3x from each side

-8 = 5x+4

subtract 4 from each side

-12 = 5x

divide -12 by 5 to get x

x = -12/5 = -2.4

3 0