Answer:
3. glad to help
Step-by-step explanation:
Answer:
D. 59.66
Step-by-step explanation:
The formula is <em>A =
= 3.14</em>
so we need to find the area's
9 x 9 = 81
81 x 3.14 = 254.34
Next circle.
10 x 10 = 100
100 x 3.14 = 314
Now to find the difference.
314 - 254.34 = 59.66
59.66
Hope this helped! Please mark as brainliest! Thanks!
5*1/5+1/5*15=4
1 + 3 =4
This should equal 4 if I did this correctly.
Answer: 7299, 7301
Step-by-step explanation:
x + x + 2= 14,600
2x = 14,598
x = 7,299
Therefore, the office numbers are 7299 and 7301
Answer:
<u>The company should promote a lifetime of </u><u>3589 hours</u><u> for these bulbs, so that only 2% of them burnout before the claimed lifetime.</u>
Step-by-step explanation:
Consider the lifetime of light bulbs is normally distributed. Then, μ = 4000 hours and σ = 200 hours.
Let X be the lifetime of bulbs. We need to find the lifetime before which only 2% (0.02) of the bulbs burn out. Suppose the value of this lifetime is y. then, we need to find out P(X<y) = 0.02.
We will use the z-score formula:
<u>z = (x-μ)/σ</u>
P(X<y) = 0.02
P((X-μ)/σ < (y-μ)/σ) = 0.02
P(z < (y-4000)/200) = 0.02
We can find the value of z at which the probability is 0.02 from the normal distribution (areas under the normal curve) table.
From the table we can see that 0.02 lies between z values -2.05 and -2.06. So,
z = [-2.05 + (-2.06)]/2
= -4.11/2
z = -2.055
So,
(y-4000)/200 = -2.055
y-4000 = -411
y = 4000 - 411
y = 3589 hours
<u></u>
<u>The company should promote a lifetime of </u><u>3589 hours</u><u> for these bulbs, so that only 2% of them burnout before the claimed lifetime.</u>