In a mid-size company, the distribution of the number of phone calls answered each day by each of the 12 receptionists is bell-shaped and has a mean of 37 and a standard deviation of 9. using the empirical rule (as presented in the book), what is the approximate percentage of daily phone calls numbering between 28 and 46?

0.6826

Step-by-step explanation:

Mean(μ) = 37

Standard deviation (σ) = 9

P(28 < x < 46) = ???

Using normal distribution

Z = (x - μ)/σ

For x = 28

Z = (28 - 37)/9

Z = -9/9

Z = -1

For x = 46

Z = (46 - 37)/9

Z = 9/9

Z = 1

We now have

P(-1 < Z < 1)

= P(Z < 1) - P(Z < -1)

From the table, Z = 1 = 0.3413

φ(Z) = 0.3413

Recall that

When Z is positive, P(x<a) = 0.5 +φ(Z)

P(Z<1)= 0.5 + 0.3413

= 0.8413

When Z is negative, P(x<a) = 0.5 - φ(Z)

P(Z< -1)= 0.5 - 0.3413

= 0.1587

We now have

0.8413 - 0.1587

= 0.6826

plants store their excess carbohydrate in the form of starch so that it could be used as energy source later on. the excess carbohydrate is converted into starch in the plastid i.e. chloroplast & this process occurs in the presence of sunlight. it is an insoluble polymer of glucose which gets stored in cell organelles named as amyloplasts. in some plants, starch is also stored in roots and embryos.

answer: 7

step-by-step explanation: