Helen draws a random circle. She then measures its diameter and circumference.
She gets a circumference, C, of 405 mm correct to 3 significant figures.
She gets a diameter, d, of 130 mm correct to 2 significant figures.
Helen wants to find the value of Pi
using the formula pi=C/D
Calculate the lower bound and upper bound for Helen's value of it.
Give your answers correct to 3 decimal places.​

Do social recommendations increase ad effectiveness? a study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. the results are given below.correctly recalled the brandarrival 409153browsing20484b. conduct the hypothesis test, using the 0.025 level of significance.what is the value of the test statistic? χ2stat=what is the p-value? p-value=is this value significant atα=0.025?

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

Write a description of each inequality. 1. -5a + 3 > 1 2. 27 - 2b < -6 (this < has a _ under it) 3. 1/2 (c + 1) > 5 (this > has a _ under it)