Question

Donna mean score in four test is 65 .Three of her test scores are 65,82,69.
a. What is the Donna fourth score?
b.Does wants to in her mean score to 70. How many marks should she make in her fifth test to reach the mean score of 70?​

Answer 1

Answer:

a. 44

b. 90

Step-by-step explanation:

a. Let the fourth test's marks of Donna be x

given mean score of her four test = 65

so, (65+82+69+x)/4 = 65

⇒ 216 + x = 260

⇒x = 260 - 216

⇒ x = 44

b. If Donna wants her mean score to be 70 in 5 tests then

Let the fifth test's marks of Donna be y

then, (65+82+69+44+ y)/5 = 70

⇒260+y = 350

⇒ y = 90