Crawling data collected by child development scientists pro- duced this confidence interval for the average age (in weeks) at which babies begin to crawl: t-interval for m 30.65 6 m(age) 6 32.89 (95.00% confidence): a) explain carefully what the software output means. b) what is the margin of error for this interval

a) We can be 95% sure that true average age (in weeks) at which babies begin to crawl is between 30.65 weeks and 32.89 weeks.

b) Margin of error for the confidence interval is 1.12 weeks.

Step-by-step explanation:

Let m be the estimate of the average age (in weeks) at which babies begin to crawl

Let ME be the margin of error.

then the difference between the upper bound and the lower bound gives:

m+ME - (m-ME) = 2ME = 32.89-30.65=2.24 which gives

ME=1.12 weeks

24/56=hx^7

step-by-step explanation:

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form