Ask question

Ask question

All categories

3 years ago

10

The amount of time a certain brand of light bulb lasts is normally distributed with a

1 answer:

scoundrel [369]3 years ago

5 0

Answer:

92.65 % light bulbs last less than 2080 hours

Step-by-step explanation:

We are given that The amount of time a certain brand of light bulb lasts is normally distributed

Mean = $\mu = 2000$

Standard deviation = $\sigma = 55$

We are supposed to find What percentage light bulbs last less than 2080 hours, to the nearest tenth

$Z = \frac{x-\mu}{\sigma}\\\\Z=\frac{2080-2000}{55}$

Z=1.45

Refer the z table for p value

p value = 0.9265

Hence 92.65 % light bulbs last less than 2080 hours

You might be interested in

The table gives the average age of airplanes per airline at Camila’s local airport. By what percent is the number of airlines wi

VladimirAG [237]

The percentage that the number of airlines with an average airplane age of 14 is less than the number of airlines with an average airplane age of 11 is:

B. 20%.

<h3>What is a percentage?</h3>

The percentage of an amount a over a total amount b is given by a multiplied by 100% and divided by b, that is:

$P = \frac{a}{b} \times 100\%$

The percentage of airlines with an average age of 14 years is:

$P = \frac{2}{15} \times 100\% = 13.33\%$

The percentage of airlines with an average age of 11 years is:

$P = \frac{5}{15} \times 100\% = 33.33\%$

The difference is:

33.33% - 13.33% = 20%.

Hence option B is correct.

More can be learned about percentages at brainly.com/question/10491646

#SPJ1

6 0

2 years ago

Find the area of the figure

Amanda [17]

Answer:

A ≈ 26.42

Step-by-step explanation:

<em><u>The shape presented is a circle, and the formula for this is:</u></em>

A = π $r^2$

<em><u>The "</u></em> $r$ <em><u>," is the radius (2.9), so plug this into the formula:</u></em>

A = π $(2.9)^2$

A = π8.41

A ≈ 26.42

4 0

4 years ago

What is the surface area?

Alchen [17]

Answer:

SA: 1575.2

Step-by-step explanation:

(22)(22) + (26)(22) = (23.6)(22)

484 + 572 + 519.2 = 1575.2

I hope I helped you ;)

6 0

3 years ago

Anyone help me. ....

weeeeeb [17]

Answer:

see explanation

Step-by-step explanation:

Using the rules of exponents

All the exponents inside the parenthesis are multiplied by the exponent outside the parenthesis.

Then

$\frac{m^{-7}n^{14} }{m^{-25}n^{40} }$ ÷ $\frac{m^{-21}n^{42} }{m^{-25}n^{40} }$

[ Using the rule $\frac{a^{m} }{a^{n} }$ = $a^{(m-n)}$ ]

= $m^{(-7-14)}$ $n^{(14-(-28)}$ ÷ $m^{(-15-10)}$ $n^{(25-(-15)}$

= $m^{-21}$ $n^{14+28}$ ÷ $m^{-25}$ $n^{25+15}$

= $\frac{m^{-21}n^{42} }{m^{-25}n^{40} }$

= $m^{(-21-(-25))}$ $n^{(42-40)}$

= $m^{(-21+25)}$ n²

= $m^{4}$ n² = $m^{x}$ $n^{y}$ , so x = 4 and y = 2

Then

$m^{x-2y}$ = $m^{4-2(2)}$ = $m^{4-4}$ = $m^{0}$ = 1 ← as required

6 0

3 years ago

Write the equation of the line perpendicular to 3x+y=-8 that passes through (-3,1) . Write your answer in slope-intercept form.

murzikaleks [220]

I hope this helps you

3 0

3 years ago

Read 2 more answers