Answer:
a = 14
Step-by-step explanation:
3a = a + 28 ➡ 2a = 28 ➡ a = 14
I think it will take Elizabeth 17 minutes.
Answer:
(a)
radius=diameter/2
=21/2=10.5m
(b)
radius=diameter/2
=3.25/2=1.625mm
I would appreciate if my answer is chosen as a brainliest answer
Answer:
The probability that <em>X</em> is less than 42 is 0.1271.
Step-by-step explanation:
The random variable <em>X </em>follows a Normal distribution.
The mean and standard deviation are:
E (X) = <em>μ</em> = 50.
SD (X) = <em>σ</em> = 7.
A normal distribution is continuous probability distribution.
The Normal probability distribution with mean µ and standard deviation σ is given by,

To compute the probability of a Normal random variable we first standardize the raw score.
The raw scores are standardized using the formula:

These standardized scores are known as <em>z</em>-scores and they follow normal distribution with mean 0 and standard deviation 1.
Compute the probability of (X < 42) as follows:

*Use a <em>z</em>-table for the probability.
Thus, the probability that <em>X</em> is less than 42 is 0.1271.
The normal curve is shown below.
You could round 77 to 80 and 65 to 70 and then add 70 and 80 and you will get 150