Answer:
The mean of the total repair time is 150 minutes.
The variance of the total repair time is 725 minutes^2.
Step-by-step explanation:
To solve this problem, we have to use the properties of the mean and the variance. Our random variable is the sum of 3 normal variables.
In the case, for the mean, we have that the mean of the sum of 3 normal variables is equal to the sum of the mean of the 3 variables:
For the variance, we apply the property for the sum of independent variables (the correlation between the variables is 0):
The first time is 4 over 5 and the second time is 1 over 5
Answer:
42
Step-by-step explanation:
Answer:
Option D is correct i.e angle B is 55°
Step-by-step explanation:
Given In triangle ABC, a=7, b=10 and angle C is a right angle.
we have to find the angle B.
As given triangle is right angled triangle,
∴ we can apply the formula of trigonometric ratios to find the angle B
⇒ 
Hence, angle B is 55°
Option D is correct.
Answer:
a) The bacterium is longer;
b) The bacterium is 0.1543 mm longer than the yeast.
Step-by-step explanation:
In order to compare the length of the two beings we need to convert them to the same unit. We can do it either way, but we'll choose to convert from meters to milimetres, since we're dealing with small numbers. To do that we need to multiply the length that is in "m" by 1000.
a) The bacteria is longer than the yeast.
b) We need to subtract their length in order to find this answer:
