1) 8 bananas cost £4<br><br> Work out the cost of 5 bananas.

The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 mi

dem82 [27]

Answer:

62.17% probability that a randomly selected exam will require more than 15 minutes to grade

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 16.3, \sigma = 4.2$

What is the probability that a randomly selected exam will require more than 15 minutes to grade

This is 1 subtracted by the pvalue of Z when X = 15. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{15 - 16.3}{4.2}$

$Z = -0.31$

$Z = -0.31$ has a pvalue of 0.3783.

1 - 0.3783 = 0.6217

62.17% probability that a randomly selected exam will require more than 15 minutes to grade

8 0

2 years ago

What is 2 divide by 36

Schach [20]

Answer:

0.0555555556

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

If P(AnB)=2/3 and P(B)=3/4, what is P(A I B)? A.35/36 B.15/16 C.24/25 D.8/9

astraxan [27]

Answer:

$\large\boxed{D.\ \dfrac{8}{9}}$

Step-by-step explanation:

$\text{We know:}\\\\P(A|B)=\dfrac{P(A\ \cap\ B)}{P(B)}\\\\\text{We have:}\\\\P(A\ \cap\ B)=\dfrac{2}{3},\ P(B)=\dfrac{3}{4}.\\\\\text{Substitute:}\\\\P(A|B)=\dfrac{\frac{2}{3}}{\frac{3}{4}}=\dfrac{2}{3}:\dfrac{3}{4}=\dfrac{2}{3}\cdot\dfrac{4}{3}=\dfrac{8}{9}$

6 0

3 years ago

What is (-8.1)-(-8.9)

polet [3.4K]

Answer:

0.8

Step-by-step explanation:

-8.1+8.9=0.8

so the answer is 0.8

5 0

1 year ago

Read 2 more answers

Let t be time in seconds and let r(t) be the rate, in gallons per second, that water enters a reservoir: r(t)=700−40t. a) For 0≤

Flura [38]

What you don't want is the value of r(t) becoming negative. Surely that would represent water escaping the reservoir.

How big can (t) get before water actually starts escaping the reservoir?

Essentially, to figure this out r(t) would have to be equal to 0.

700 - 40t = 0

40t=700

t=700/40=17.5

So the first answer is 17.5 seconds. After this amount of time has elapsed the reservoir will start to lose water as r(t) would become negative.

---------------

The reservoir had the least amount of water in it before it was being filled. That was when t=0. The volume of water in the reservoir wasn't negatively impacted as not enough water had escaped it during the 17.5 to 30 second period.

7 0

2 years ago

1) 8 bananas cost £4 Work out the cost of 5 bananas.