<span>Probability = 0.063 Fourth try = 0.0973 Let X be the number of failed attempts at passing the test before the student passes. This is a negative binomial or geometric variable with x â {0, 1, 2, 3, . . .}, p = P(success) = 0.7 and the number of successes to to observe r = 1. Thus the pmf is nb(x; 1, p) = (1 â’ p) xp. The probability P that the student passes on the third try means that there were x = 2 failed attempts or P = nb(2, ; 1, .7) = (.3)2 (.7) = 0.063 . The probability that the student passes before the third try is that there were two or fewer failed attmpts, so P = P(X â‰¤ 2) = nb(0, ; 1, .7) + nb(1, ; 1, .7) + nb(2, ; 1, .7) = (.3)0 (.7) + (.3)1 (.7) + (.3)2 (.7) = 0.973 .</span>

4 0

3 years ago

Kendall had $1000 in a savings account at the beginning of the semester. She has a goal to have at least $350 in the account by

USPshnik [31]

Answer:

11 weeks

Step-by-step explanation:

First we need to check what variables we have.

Beginning Balance = $1000

Goal = $350

Withdrawal = $55 per week

Now let's declare a variable as the number of weeks.

Let x = number of weeks

1000 - 55x = 350

-55x = 350-1000

-55x = -650

Then we divide both sides by -55 to find the value of x.

x = 11.81 or 11 since we're looking for how many weeks in total

Now let's see if we still have 350 if we have a total of 11 as the value of x.

1000 - 55(11) = 350

1000 - 605 = 350

395 = 350

We can see that Kendall will have $395 compared to the $350 goal.

So Kendall can withdraw $55 a week for 11 weeks to still be within her goal of having $350 in her savings account.

6 0

3 years ago

One fourth of 12 bottles of water equals how many bottles

likoan [24]

One-fourth of 12 bottles of water would equal 3 bottles of water

7 0

3 years ago