What is the volume of this pyramid?

Alex scored 98,72, and 87 on his first three math test. What must he score on the next test to have an average of at least 86 (P

ss7ja [257]

Answer:

$\huge\boxed{\text{At least an } 87\%}$

Step-by-step explanation:

In order to find what score Alex must earn to have an average of 86 on all his tests, we need to first note what the formula to find the average of a data set is.

$\displaystyle \frac{x_1+x_2+...x_n}{n}$

What the formula means is that we have to add up all the values then divide by the total number of values.

Let's represent our unknown number as $x$ .

$\displaystyle \frac{98+72+87+x}{4} \geq 86$ (since we want AT LEAST an 86).

Let's solve this inequality for x.

$\frac{98+72+87+x}{4} \cdot 4 \geq 86 \cdot 4$
$98+72+87+x \geq 344$
$257 + x \geq 344$
$257 + x - 257 \geq 344 - 257$
$x \geq 87$

So, Alex must score at least an 87% on his next quiz to have an average of 86%.

Hope this helped!

8 0

2 years ago

A slide that Baker Park has a height of 10 feet and is 15 feet long. How high are you off the ground when you are 6 feet down th

ss7ja [257]

Answer:

4 ft

Step-by-step explanation:

just look at the length of the slide and substract it.

10-6=4

4 0

3 years ago

Read 2 more answers

The mean height of women in a country (ages 20-29) is 64 4 inches A random sample of 50 women in this age group is selected What

Simora [160]

Answer:

0.0721 = 7.21% probability that the mean height for the sample is greater than 65 inches.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .