Question

STATISTICS PLEASE HELP!!!
a researcher notes that the weight of a male golden retriever is approximately normally distributed with a mean of 70 lbs and a standard deviation of 7.5 lbs. what percentage of these dogs weigh less than 65 lbs?


a. 75%

b. 25%

c. 5%

d. 33.3%

e. 66.7%


STATISTICS QUESTION, PLEASE HELP AND EXPLAIN!

Answer 1

Answer:

b

Step-by-step explanation:

With so many question of statistics I had to go looking for a Z table.

Ok so in order to know an accurate percentage in a normal distribution you calculate Z:

$z = (x - mean) \div (st \: dev)$

Z = (65 - 70)/7.5 = - 0.667

Then you enter Z in a Z-Table (there are many Z-table so be careful how you use it)

And the probability for a Z of - 0.667 is ~25%