Question

Select the correct answer

Gavin collects a certain type of seashell. He has 160 seashells. The seashells' weights are distributed normally, with a mean of 120 grams and a

standard deviation of 26 grams.


How many of the seashells weigh at least 68 grams?

A 134

В.152

C.156

D. 109

Answer 1

156/C

Explanation:

#platolivesmatter

Answer 2

Answer: C.156

Explanation:

Given: Total seashells = 160

mean = 120

population standard deviation = 26 grams

The probability that the seashells weigh at least 68 grams :-'

`P(X\geq68) =P((x-\mu)/(\sigma)\geq(68-120)/(26))\\\\=P(z\geq-2)\\\\=P(z<2)\ \ \ [P(Z\geq-z)=P(Z<z)]\\\\= 0.9772\ \ \ [\text{By p-value table}]`

Total seashells weigh at least 68 grams = 0.9772 x 160 = 156.352≈ 156

Hence, the correct option is C.156