hi there just need help with these two if possible ?

The diameter (in millimeters) for 34 sand dollar (Dendraster excentricus) shells (tests) collected from beaches in Morro Bay was measured. A stem-and-leaf plot constructed from this sample data appears below. N 5 6 0 1 1 2 3 4 4 5 7 3 3 5 6 8 9 9 2 1 4 4 6 7 0 2 4 Use this data with a = 5% to test the validity of the hypothesis that, for beaches in Morro Bay, the mean sand dollar shell diameter is 45 mm.Students collected data for their Elementary Statistics class project by asking every tenth Sierra College student that exited the cafeteria on the Rocklin campus the question "Which company manufactures their mobile phone?". The following sample results were obtained. Apple, Apple, Samsung, Apple, LG, Apple, Apple, Samsung, Apple, Samsung, Apple, Motorola, Samsung, Apple, Apple, HTC, Samsung, Apple, Apple, LG, Samsung, Apple, HTC, Apple, LG, Samsung, Apple, Samsung, Motorola, Samsung, Motorola, Apple, Samsung, LG, Apple, Apple, Apple, LG, Samsung, Apple, Apple, HTC, Samsung, Motorola, Apple, Samsung Estimate the percentage of Sierra College students that have a mobile phone manufactured by Motorola. Express the estimate both symbolically and verbally