Atoy manufacturer wants to know how many new toys children can buy each year. he thinks the mean is 6.9 toys per year. assume a previous study found the standard deviation to be 1.3. how large a sample would be required in order to estimate the mean number of toys bought per child at the 98% confidence level with an error at most 0.11 toys?

758

Step-by-step explanation:

Given : Mean :

Standard deviation :

Margin of error :

Significance level :

Critical value :

Formula for sample size  :-

Hence, the minimum required sample size = 758

5x+2x=49

7x=49

x=7. 35 apples

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.