Thickness measurements of ancient prehistoric Native American pot shards discovered in a Hopi village are approximately normally distributed, with a mean of 5.4 millimeters (mm) and a standard deviation of 0.8 mm. For a randomly found shard, find the following probabilities. a. the thickness is less than 3.0 mm
b. the thickness is more than 7.0 mm
c. the thickness is between 3.0 mm and 7.0 mm

a) the required probability is 0.0013

b) the required probability is 0.0288

c) the required probability is 0.9759

Step-by-step explanation:

Given the data in the question;

let x be the thickness measurements

Given that X follows a Normal distribution with mean μ = 5.4

standard deviation σ = 0.8

then z = x-μ / σ = x-5.4 / 0.8   follows standard Normal

a) probability that the thickness is less than 3.0 mm

P( x<3 ) = P( x-5.4 / 0.8  <  3-5.4 / 0.8 ) = P( Z < -3.00 ) = 0.0013

Therefore, the required probability is 0.0013

b) the thickness is more than 7.0 mm

P( x>7 ) = P( x-5.4 / 0.8  >  7-5.4 / 0.8 ) = P( Z > 2.00)

= 1 - P( Z ≤ 2)

= 1 - 0.9772

= 0.0288

Therefore, the required probability is 0.0288

c) the thickness is between 3.0 mm and 7.0 mm

P(3< x<7 ) = P( x<7) - P(x<3)

= P( x-5.4 / 0.8  >  7-5.4 / 0.8 )  - P( x-5.4 / 0.8  <  3-5.4 / 0.8 )

= P( Z< 2 ) - P( Z < -3)

= 0.9772 - 0.0013

= 0.9759

Therefore, the required probability is 0.9759

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.

17.08

correct me if i am wrong.