Astudent answers all 48 questions on a multiple-choice test by guessing. each question has four possible answers, only one of which is correct. find the probability that the student gets exactly 15 correct answers. use the normal distribution to aproximate the binomial distribution.

0.7967
0.0606
0.0823
0.8577

Correct answer is C

Step-by-step explanation:

First we need to find expected value of the event:

And standard deviation of the event:

Then need to z value of normal distribution function for 15.5 and 14.5 correct answers:

P(15)=0.8790-0.7967=0.0823

Ps. Please find z table at the attachment.

6 spoons of sugar for every 21 cups of flour

step-by-step explanation:

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.