All categories

3 years ago

Most evenings after dinner Duarte spends 30 minutes playing chess with his dad.

1 answer:

7 0

T= total played
e= # evenings played
m= # minutes played

Total equals number of evenings played multiplied by number of minutes plated per evening.

EQUATION:
t=e * m

EQUATION (if 30 minutes per evening):
t=30e

Example:
3 nights, 30 minutes played

t= 3 * 30
t=90 minutes total played

Hope this helps! :)

You might be interested in

What is the smallest of 3 consecutive positive integers if the product of the smaller two integers is 5 less than 5 times the la

olga55 [171]

Let's say the first number is "a"
the next consecutive can just be "a+1" and the next, you guessed it, "a+2"
the two smaller ones are a and a+1, the larger one is a+2

now, the product of "a" and "a+1" equals 5 times "a+2" but less by 5

thus a(a + 1) = 5(a + 2) - 5 <----- solve for "a"

7 0

3 years ago

Darcia made a snack mix using the following recipe. 1 ¼ cups granola, ¾ cup peanuts, ½ cup raisins, ¼ cup chocolate chips. If sh

Elden [556K]

Answer:

2345

Step-by-step explanation:

because3456

5 0

3 years ago

While researching the cost of school lunches per week across the state, you use a sample size of 45 weekly lunch prices. The sta

Drupady [299]

We assume the lunch prices we observe are drawn from a normal distribution with true mean $\mu$ and standard deviation 0.68 in dollars.

We average $n=45$ samples to get $\bar{x}$ .

The standard deviation of the average (an experiment where we collect 45 samples and average them) is the square root of n times smaller than than the standard deviation of the individual samples. We'll write

$\sigma = 0.68 / \sqrt{45} = 0.101$

Our goal is to come up with a confidence interval (a,b) that we can be 90% sure contains $\mu$ .

Our interval takes the form of $( \bar{x} - z \sigma, \bar{x} + z \sigma )$ as $\bar{x}$ is our best guess at the middle of the interval. We have to find the z that gives us 90% of the area of the bell in the "middle".

Since we're given the standard deviation of the true distribution we don't need a t distribution or anything like that. n=45 is big enough (more than 30 or so) that we can substitute the normal distribution for the t distribution anyway.

Usually the questioner is nice enough to ask for a 95% confidence interval, which by the 68-95-99.7 rule is plus or minus two sigma. Here it's a bit less; we have to look it up.

With the right table or computer we find z that corresponds to a probability p=.90 the integral of the unit normal from -z to z. Unfortunately these tables come in various flavors and we have to convert the probability to suit. Sometimes that's a one sided probability from zero to z. That would be an area aka probability of 0.45 from 0 to z (the "body") or a probability of 0.05 from z to infinity (the "tail"). Often the table is the integral of the bell from -infinity to positive z, so we'd have to find p=0.95 in that table. We know that the answer would be z=2 if our original p had been 95% so we expect a number a bit less than 2, a smaller number of standard deviations to include a bit less of the probability.

We find z=1.65 in the typical table has p=.95 from -infinity to z. So our 90% confidence interval is

$( \bar{x} - 1.65 (.101), \bar{x} + 1.65 (.101) )$

in other words a margin of error of

$\pm 1.65(.101) = \pm 0.167$ dollars

That's around plus or minus 17 cents.

3 0

3 years ago

Read 2 more answers

A bean salad has 20 beans in all. It is made up of:

vlabodo [156]

10 Lima beens
8 red beans
2 black-eyed beans

3 0

2 years ago

1E. The number 2A5A0A2 is divisible by 99. What is the digit A?

kirza4 [7]

Answer: A = 3

Step-by-step explanation:

The digit is 3. If A is 3, the number

2A5A0A2 becomes 2353032. We then divide by 99 and this will be:

= 2353032/99

= 23768

If we use 1, we'll have 2151012. Dividing by 99 gives:

= 2151012 / 99

= 21727.39

If we use 2, we'll have 2252022. Dividing by 99 gives:

= 2252022 / 99

= 22747.69

If we use 4, we will have 2454042. Dividing by 99 gives:

= 2454042 / 99

= 24788.30

If we use 5, we will have 2555052. Dividing by 99 gives:

= 2555052 / 99

= 25808.61

If we use 6, we will have 2656062. Dividing by 99 gives:

= 2656062 / 99

= 26828.91

If we use 7, we will have 2757072. Dividing by 99 gives:

= 2757072 / 99

= 27849.21

If we use 8, we will have 2858082. Dividing by 99 gives:

= 2858082 / 99

= 28869.52

If we use 9, we will have 2959092. Dividing by 99 gives:

= 2959092 / 99

= 29889.82

If we use 0, we will have 2050002. Dividing by 99 gives:

= 2050002 / 99

= 20707.09

Therefore, A is 3 as it gives 2353032 which divides 99 successfully without remainder.

5 0

3 years ago