Which algebraic expression is equivalent to the expression below 6 parentheses 2x + 7 parentheses -5

KatRina [158]

Answer:

first and second choice

5 0

3 years ago

A collection of 5 positive integers has mean 4.4, unique mode 3 and median 4. If an 8 is added to the collection, what is the ne

Sphinxa [80]

9514 1404 393

Answer:

4.5

Step-by-step explanation:

It appears the 5 integers must be {3, 3, 4, 5, 7}.

For the mode to be unique, there must be more than one '3', and there cannot be any other repeated numbers. For 4 to be the median, it must be the 3rd-highest number. Then the remaining numbers must be integers greater than 4 with a sum of 12 for the mean to be 4.4.

When 8 is added to the collection, the median is now the average of 4 and 5, so is 4.5.

The new median is 4.5.

_____

Comment on vocabulary

mean: the sum of numbers divided by the number of numbers. 5 numbers with a mean of 4.4 will have a sum of 5×4.4 = 22.

median: the middle number of a collection of an odd number of numbers, when sorted from lowest to highest. It is the 3rd number of a group of 5 numbers. When there are an even number of numbers in the group, the median is the average of the middle two in the sorted list. Here, that means the 3rd number in the list of 5 is '4'. When 8 is added, 4 becomes one of the numbers contributing to the average that will be the new median.

mode: the member of the group that appears the most times. When the mode is unique, it means there are no other numbers repeated as often. Here, we know the 3rd number (of 5) is 4, so there can only be two numbers '3' in the collection. That 3 is the unique mode means no other numbers are repeated at all.

8 0

3 years ago

A bar gr agh shows that sports books received 9votes .if the scale is 0to20 by twos ,where should the bar end for the sports boo

Viefleur [7K]

Between 8 and 10. Because the number graph goes in two's and not in one's, the odd numbers go in between the even numbers.

8 0

3 years ago

Simplify the fraction completely.

k0ka [10]

Answer:

5

Step-by-step explanation:

40% means 40 parts out of 100. If we have made the numerator of the fraction 2, we have divided 40 by 20. To make this fraction equal to 40/100, we have to divide 100 by 20 as well, giving us 5.

3 0

2 years ago

Read 2 more answers

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is regi

yan [13]

Answer:

We conclude that the percentage of employed workers who have registered to vote exceeds the percentage of unemployed workers who have registered to vote.

Step-by-step explanation:

We are given that 513 employed persons and 604 unemployed persons are independently and randomly selected, and that 287 of the employed persons and 280 of the unemployed persons have registered to vote.

Let $p_1$ = percentage of employed workers who have registered to vote.

$p_2$ = percentage of unemployed workers who have registered to vote.

So, Null Hypothesis, $H_0$ : $p_1\leq p_2$ {means that the percentage of employed workers who have registered to vote does not exceeds the percentage of unemployed workers who have registered to vote}

Alternate Hypothesis, $H_A$ : $p_1>p_2$ {means that the percentage of employed workers who have registered to vote exceeds the percentage of unemployed workers who have registered to vote}

The test statistics that would be used here Two-sample z test for proportions;

T.S. = $\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }$ ~ N(0,1)

where, $\hat p_1$ = sample proportion of employed workers who have registered to vote = $\frac{287}{513}$ = 0.56

$\hat p_2$ = sample proportion of unemployed workers who have registered to vote = $\frac{280}{604}$ = 0.46

$n_1$ = sample of employed persons = 513

$n_2$ = sample of unemployed persons = 604

So, the test statistics = $\frac{(0.56-0.46)-(0)}{\sqrt{\frac{0.56(1-0.56)}{513}+\frac{0.46(1-0.46)}{604} } }$

= 3.349

The value of z test statistics is 3.349.

Now, at 0.05 significance level the z table gives critical value of 1.645 for right-tailed test.

Since our test statistic is more than the critical value of z as 3.349 > 1.645, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that the percentage of employed workers who have registered to vote exceeds the percentage of unemployed workers who have registered to vote.

5 0

3 years ago